jarrod0987
Aquarium Advice FINatic
- Joined
- Jul 12, 2005
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As many of you know I am very interested in Algae in aquariums. Mostly the killing and preventing of it. I have been actively focused on it since 99. I have read many articles and study many subjects to also include ponds, waste water treatment and basic inorganic chemistry. I have recently read a book on Phycology which is the study of Algae. Honestly, it was written for a microbiologist to read and most of it is way over my head. I did, however, pic up some very cool tips that I don't think are commonly known in the hobby about certain types of algae. I decided to share those and all my other insights and experiences in one massive article.
I will first cover the general approach to algae and philosophies about it. Then I will cover specific types of freshwater algae case studies. Then the same thing for Salt Water. Reference Resources are at the end.
Algae approaches
the problem with reading about algae in the web is that just about everything in the aquarium as far as equipment and chemistry has been blamed for it. The truth is that there is no one thing that causes algae or a certain type of algae. There are defiantly some things that are major contributors and some things that are minor contributors. I will classify things in this way.
It is important to understand that different types of aquariums approach algae with different strategies. I will the generally accepted practices here. I will like to point out that just because something is commonly practiced or believed does not make it the best way or even right. Part of the reason I am writing this article is to stir up the hobby and get people to let go of old ideas and keep looking for new methods.
Generally speaking, in Fresh Water Fish Only Systems, the approach is to control nutrients with water changes.
Same Thing in Salt Water Fish only Systems but those people are also willing to use chemical means to remove nutrients from there water to a much lower level than water changes can provide. In Particular they love the use of GFO to remove phosphate. This has Helped a lot to keep aquariums clear of algae. Some of them also use combinations of Skimmers and Activated Carbon to remove organics. The cutting edge is to use Carbon Dosing to remove Nitrates. All these things have really helped us keep our Salt Water Aquariums clear of algae. They also use clean up crews to get the last little bit. Snails and crabs etc. They also use plants sometimes to remove the nutrients.
In Fresh Water Planted tanks people use a very different approach. Instead of focusing on removing algae they focus on healthy plants. When the plants are healthy the algae is usually just barley present if at all. People debate why but it seems to be the case. Some of them load up there water with certain ratios of nutrients while others add tiny daily doses of nutrients and never let them build up. These are the hardest systems to battle algae because you have to provide nutrients to the plant which algae also needs. Plant people will argue for decades over the many planted tank approaches.
In Salt Water Reef (Coral) systems people have traditionally taken a no nutrient approach. They use water changes and various chemical means to strip all the nutrients out. Until recently it was not possible to remove them all the way. Now that it is possible, we found it causes our corals are not healthy if we do that. So we now have to maintain low levels of nutrients to get good coral health, growth, and color. I would like to say that those of you who think Reef tanks are beautiful but you are afraid of the chemistry that it is all the same chemicals from the planted tank hobby. Just different levels and equipment. Don't miss out
Light
Light has long been blamed for algae. On of the first fish stores I ever shopped at way back in 98 had a switch by the counter to control the lights for all the tanks. When a customer walked in, Lights went on. Soon as they left, Lights went off. Also algae eaters were used.
To this day I have had managers at certain Chain Stores tell me that light is the cause. Just turn off the light and you won't have any. That's probably true but why sell me a light I can't use? Don;t worry. I love a bright tank and I have very little algae in all my tanks. I will teach you. For now just know that How bright, How long, and what color (Wavelength) a light is can have an effect. Light does not cause algae any more then any other one factor does. What causes algae is an environment that the algae prefers and light is a part of that. Replacing old bulbs and lowering the amount of daylight hours can help slow algae down. In my experience it has never really solved any of my algae cases. I classify it as a minor factor but I do concede that exposing a tank with nutrients present to daylight, bright light, or long photo periods can cause problems.
Case Study:
I recently talked to a fellow hobbyist who has a lot of experience with breeding. She was using Salt water bulbs over her freshwater tank for years with no problems. The myth is that this should have caused huge algae outbreaks because she was not using the right spectrum. I use those bulbs too because I like a white light vs a yellow light in my tanks. Myth Busted
Flow and substrate.
Some people believe low flow is a contributing factor to algae and have stated that increasing there flow got rid of there algae problem. I have seen similar things. With low flow the fish waste is no longer being suspended in the water long enough for the mechanical filtration to remove it. It settle to the bottom and rots. This releases loads of nutrients into the water. It increases over time until you reach a tipping point where the algae explodes.
Having inadequate pumps can cause this but so does Gravel. I classify low pump speed as a minor factor.
Substrate (Sand and Gravel)
When water flows over a fairly flat bottom such as glass or sand it does not slow down that much. When it flows over rocks or gravel or decorations it has to change directions. It bounces off and looses all it's energy so it slows down and all the waste falls out. I no longer prefer gravel in any of my systems for this reason. Nothing but problems. Also shrimp cannot get down into the gravel to eat the waste but they can turn over sand grains very nicely.
Some substrates can release high levels of iron or phosphate into the water. Some can release higher alkalinity which is a good thing. If your using plain sand or gravel you don't have to worry about this. I
I have had a lot of algae cases because of this property of gravel. Deep gravel is even worse. I classify Gravel as a major factor.
Temp
Something I found out years ago that no one ever talks about is that certain types of algae (mentioned later) prefer warm water. So keeping the temperature higher then you need to is a minor factor in certain cases.
pH and Alkalinity (kH)
pH and Alkalinity (also known as kH) are closely tied together. I am not going to get into that discussion here except to say the more alkalinity the higher and more stable the pH. Many types of green algae seem to die off in more alkaline waters. They seem to prefer acidic or lower pH water. I have heard many people argue bitterly over weather Alkalinity or Nutrients are the main factor of algae. I like my tanks at a higher (but still in safe range for my species) alkalinity. I have few algae problems in any of my tanks. I classify Alkalinity as a major factor (Especially in salt water tanks).
Nutrients (Level and Ratio)
We are now going to start a major discussion about nutrients and how they can lead to algae. This section is very controversial. What is not controversial is that pretty much everyone in the hobby agrees if you have way to many nutrients you will likely have algae problems. Unless you have no light at all. I don't like dim tanks and so I keep mine to the lowest level I can get away with and have healthy pants and corals. If I only have fish I try to strip them out completely.
Also the ratio matters. We have found that certain nutrients should be in a certain ratio. For example a 10 to 1 by ppm ratio for Nitrate to Phosphate. Example would be 10 ppm Nitrate to 1 ppm phosphate or 5 ppm nitrate to 0.5 ppm phosphate. Be aware that a phosphorus test is a little different and you have to multiply it by 3 to get the phosphate amount. We have seen that when this ratio is skewed or when nutrients are way to high that certain types of algae occur much more. I classify Nutrient levels and ratios as a major factor.
Water changes remove nutrients but also may bring them back in if they are in your tap. testing both your tank and your tap water will help you see what is happening. I have seen well water with Ammonia, city water with Phosphate, and have heard reports of nitrate in city water which is pretty bad for your health but attempts to call it in usually get ignored. The reason is most likely fear of legal action. Better just to deny it ever happened.
Next we are going to discuss specific nutrients and how much they contribute. This section is very controversial. I like that First I need to explain there are 2 main types of nutrients int he aquarium. I am going to try hard not to get to scientific. There are chemicals (Compounds) know as organic that have a whole bunch of atoms all in long chains and elaborate shapes. We can't test for them and most algae can't eat them anyways. Some are sitting on the bottom of your tank like uneaten fish food or fish poop. It would seem like they are unimportant but they actually are. The reason is because bacteria do eat them and over time they are broken down into the inorganic form (we will talk about next) which are available. It is like a slow time release of nutrients to the algae and plants over time. In some cases, you may find a tank with a huge algae outbreak but all your nutrient tests say 0. That is because there is a large amount of organics built up in the gravel or dissolved in the water. The algae eats this tiny amount instantly and so there is none left to show up on the test.
Activated carbon and Resins can help and water changes are also very important for this. I like ROX Carbon from Bulk Reef Supply. Some people say Chemipure is using this kind of Carbon along with other things like GFO or Purigen. I also love Purigen from Seachem. It does the same job but each can do a slightly different job. The particle size matters. There is a lot of overlap between these 2 products and some Cichlid keeps I know use both at the same time. I classify organics as a major contributing factor to some kinds of algae.
The next type of nutrient is inorganic and that is the only ones we can usually test for. Think of them as already broken down as much as they can be, dissolved in the water, and chemically active and available for algae, plants, or corals. The amount is important but also the ratio (Usually between Nitrate and phosphate)is important. I classify them as a major contributing factor to most kinds of algae but which one matters to which algae.
Ammonia
I am not going to cover the nitrogen cycle here. It is the price of admission. If you don't understand it go find out now. It is that important.
Like most of you I believed that my tanks never have ammonia because they are already cycled and my test kit shows there is 0 ppm anyways. Tom Barr has done a lot of research on this subject. Unfortunately his original news letters on Algae were lost and are unavailable anymore. he stated he has done experiments where he added ammonia to tank water and got green water. I have also found references to ammonia in scientific literature regarding this.
If a aquarium had no and inadequate bio filtration, or perhaps a bunch of fish were added all at once and the bacteria has not multiplied yet, algae can start to take over as ammonia builds up. What is interesting is that the API test kit may not be sensitive enough to see these trace amounts. Hanna instruments makes Ammonia Checkers now that are much more accurate and can read smaller amounts. I plant to get one some day and continue this research. For now I will say that if you see a system with green water and little biological filtration surface area (Such as bio Media, sponges, or sand) you may be looking at an ammonia issue. It probably effects other types of algae too. Some people say it is what makes a algae spore germinate into a bloom. We will talk about a green water case later on in the green water section. I classify ammonia as a major contributing factor to some kinds of algae and certainly toxic and should be addressed where ever found.
Urea
Urea is something that I never hear come up in aquarium forums at all. Tom Barr wrote an article stating when he added this to a tank he got "Stag Horn" algae. I have seen pictures but I have never had this type of algae in my tank. To add the Urea he added a lot of shrimp and snails from what I remember. Urea is a form if Nitrogen like Ammonia, Nitrite, and Nitrate are. It may show up in these test but I cannot find any info on this. I also see Urea test kits are very expensive and must be refrigerated. I classify this as probably a major factor to some types of algae but we can't test for it so not much can be said for sure.
nitrite
Nitrite is part of the nitrogen cycle and will not be around long in our tanks. In salt water it can lead to certain types of red algae. Julian Sprung has a great book on Salt Water Algae. The only time I ever saw red fuzzy algae was in a salt water fish only tank that was cycling and had high levels of nitrite for weeks. Water changes were not practice at the time. There were no fish at the time so there was no risk. When the nitrite cleared the red fuzzy algae went away too. I classify nitrite as not likely to be a factor for very long if at all.
nitrate
In the old days, when we first got nitrate test kits, it was popular to believe that nitrate was a major factor in algae and we started doing everything we could from water changes to chemicals to control it. It turns out it's probably only a minor factor. I will say that having massive amounts of Nitrate do seem to lead to green hair algae. I will also say if you have a system loaded with nitrate you have a aquarium keeper who doesn't care about there water and so it's loaded with phosphate and probably organics too. Having super high levels of nitrate probably does lead to outbreaks. Having lower levels of nitrate (say between 0 and 20 ppm) will probably have very little effect at all. I thought for a long time how to classify this one. I guess the answer is "It depends". In cases of very high nitrate, say over 40 ppm) it's probably a major contributing factor. In freshwater systems under that it's probably a minor factor but watch your ratio. In salt water systems it seems to be a much bigger contributing factor. However if your levels are under 10 ppm it is probably not your the problem. Systems with undetectable levels of nitrate (and phosphate) are usually pretty spotless but can't support plants or corals.
I will say that it's ratio to phosphate does seem important . if the ratio is skewed one way or the other, various types of algae may appear. More on that in the case studies. The ratio might be a major factor. it depends on how bad it is skewed. A minor imbalance at low levels of nitrate and phosphate is very unlikely to matter.
Nitrate can easily be removed with water changes but probably not all of it. The closer you get to 0 nitrate the more impractical this way becomes. There are also ion exchanges like Purolite which trades Nitrate for salt (only works in fresh water). I don't recommend that one. There are biological media made for it like Seachem's Matrix or Denitrate. You could also use any porous stone like pumice or other ceramic products. These have no negative effects. There is also deep sand beds. In my experience they work for a while then stop. I believe this is due to fish waste build up deep inside them. A new technique is carbon dosing which most people insist is only for salt water because you need a skimmer. That is false. You can use it in fresh water. Water treatment plants do it every day. The issue is that it makes a black bacteria sludge. You have to have a way to take it out or it will break down and add the nitrates right back. My idea would be glass bottom and a power head pointed at it to keep it stirred up. Then use regular filter floss to mechanically remove it from the water. To be honest, it's a pain in freshwater and I would go with the Matrix/Denitrate type solution in fresh water. It does work amazingly well though in salt water. Take your nitrates down to 0 ppm easily. Don;t add too much or you can cause cyano bacteria outbreaks.
In Julian Sprung's book on salt water algae most of the red algae's are associated with too much nitrate and some nitrite. I will say that the advent of Carbon dosing and bio pellets tremendously with algae prevention and control.
A long time ago....
A long time ago, maybe a decade before bio pellets or carbon dosing was a product called Deniballs. It was a carbon dosing product as far as I can tell. I always wondered about it but never bought it. It was expensive and most nitrate management products back then didn't seem to work. We all wished for a nitrate product back then because we got tired of doing massive water changes on our big tanks to try to control nitrate. I realize now the answer was right there the whole time. Props to the inventor of that product. You were way ahead of all of us.
phosphate
This is a super controversial nutrient. It comes into aquariums from the food over time. It can also come in from the tap water. The thing I only recently figured out is that massive amounts of it can come form old rocks such as "Live Rocks" from a polluted system or "Base Rock" (dead coral that came from another aquarium). Often those people had no knowledge of phosphate and let the rock soak it up in water containing 100's of ppm's of phosphate for years. That will defiantly cause algae and headaches but it takes while for it to soak back out into your water again.
In the old days a planted tank system called PMDD came out and said that having phosphate that was too high would cause algae outbreaks. It does. However, people have misinterpreted that to mean any phosphate causes algae. That is not true. However, if you strip out all the phosphate from your fish only system, I highly doubt you will see any algae. We do that mostly with Poly Filter Pads or GFO. Doing that to nitrate may work but is much harder. Doing it to Iron or Potassium will not matter either. I recommend at the very least you have a Phosphate test kit and keep it in the proper ratio with nitrate. If it is a fish only system just strip all the phosphate out with Poly Filter Pads. I promise this will put the hurting on many types of algae. Especially the green ones. If you keep plants you need to have some phosphate.
In Julian Sprung's book on salt water algae most of the green algae's are associated with too much phosphate. I will say that the advent of Phosban reactors and other GFO products helped Tremendously with algae prevention and control.
iron
Iron is equally controversial as phosphate but much easier to deal with. It gets blamed for algae sometimes and especially in farmers wells that have high iron in there water. Iron test kits only test for the one form of iron that plants and algae can use. The good news is that it doesn't stick around long n aquariums where you are not adding it on purpose. It falls right out of the water. No deed to test it unless your adding it for your plants or if you suspect your well water is highly contaminated with iron. If you get rusty stains from your shower head and toilet you might. You could use a chelator like EDTA to fix that. You could also use RO water and mix up your own. That is a whole different subject.
I will say that Iron in massive doses can cause an iron bacteria that looks nasty. I have never seen it in an aquarium.
Planted tank people often add iron. Sometimes with other "Micro ferts" and sometimes by itself. Adding massive doses of iron could cause problems but not likely IMO. They just fall out of the water anyways. Adding the other micro ferts can though. More on that soon. The only time to add Iron is if you have a planted aquarium and I recommend tiny daily doses that set your iron level to 0.1 ppm Iron. I do not recommend dosing weekly.
I was all set to classify Iron as a minor contributor at best if at all. However Planted tanks are notorious for having traces fo algae that will just not go away. Sometimes they have full on outbreaks. Usually it's too much light and/or too much fertilizer (Nutrients) in those cases. There is a tank I have been testing for about 5 months now which had traces of a green stain type algae on rocks in higher light areas as well as well as green spot algae. I tired every level and ratio of nitrate and phosphate I could find anywhere. Nothing. Due to an unrelated issue I recently started dosing tiny amounts of only Iron (no Micro ferts) daily to set th elevel to 0.1 ppm when the lights come on each day. Suddenly the green stain algae vanished from off the rocks and the green spot algae has slowed way way down. Maybe done. I was not expecting that at all. Greg Watson says in his guide that algae is often the result of a deficiency and not a surplus of nutrients. So the story on iron may not be over just yet.
Metals (Micro Ferts)
Metals have been shown to lead to algae blooms in fresh water systems. This is something that has also been heavily studied in the mining and well industries. We are talking about Metals and Heavy Metals which are toxic to fish. I can;t tell you which one causes which algae etc. I can tell you that you don;t want any of them. Examples are Aluminum, copper, manganese, zinc, cobalt, lead, Mercury, Nickle....etc. You can;t test for some of them and if you tried you would spend a lot of time and money. It is impractical. You could send a sample in to Triton Aquatics and see all of them. This is the main reason why we do water changes in our tanks. These metals build up from tap water and fish food and over time become toxic. They also can accumulate from tiny amounts in tap water or from salt mixes. They also can contribute to algae for sure. TO remove them you can use aquatic plants. Certain products remove certain ones. GFO removes Arsenic and Aluminum. Cuprisoarb removes copper. None of them remove it all. Only plants and water changes will do that for you. The hardware store sells heavy metal test but people and fish are different when it comes to toxicity so I don't think it is useful. I classify metals as a major contributing factor.
Silicate (Dissolved Sand)
Silicate is actually a major cause of a specific type of algae known as brown diatom algae. Will talk more about that soon. There are test kits. Don't buy them. Here's why. Weather you have city or well water it will probably be loaded with silicates off the chart. The brown algae comes with every new tank and then goes away on its own or gets eaten by algae eaters. After this happens the silicate levels drop down to non detectable levels and the brown algae usually never returns. You sometimes do get trace amounts inside your tubing if light hits them. It's a non issue. Don't worry about silicate. I classify it as a major but irrelevant contributing factor to Brown Diatom Algae.
spores
Transmutation was disproved a long time ago. People used to believe that rotten meat actually transformed into maggot. Science showed that it was actually flies laying eggs in the meat when no one was looking.
Algae cannot magically appear. It comes from spores just like plants come from seeds or runners. Some of those spores can travel right through the air. Some cannot. They come into your tank on fish,plants,corals, rocks, or decorations that you add. Even used equipment. Using dips might help but most people do not bother. Some of the species of algae like nasty water with lots of nutrients but some grow just fine in "Good" water. They show up in the spores find there way into your system. This probably accounts for those mysterious difficult types of algae such as Black Beard that know one can figure out where it comes from. My advice is that you buy from a dealer who does NOT have algae all over his tanks. I cannot tell you how many times I have seen a old fish keeper with a store with dim lights and yucky algae all over his tanks. Has types of algae I have never had. I bring a fish home from his system and now, 3 weeks later, I have the same thing. be very discriminatory who you buy fish and especially plants or corals from.
germination
Germination (In my non educated terms) is when an algae spore decided to come out of sleeping mode and go into algae bloom mode. Some people believe ammonia causes this. I can't say much else but I wonder of there are other factors.
I will first cover the general approach to algae and philosophies about it. Then I will cover specific types of freshwater algae case studies. Then the same thing for Salt Water. Reference Resources are at the end.
Algae approaches
the problem with reading about algae in the web is that just about everything in the aquarium as far as equipment and chemistry has been blamed for it. The truth is that there is no one thing that causes algae or a certain type of algae. There are defiantly some things that are major contributors and some things that are minor contributors. I will classify things in this way.
It is important to understand that different types of aquariums approach algae with different strategies. I will the generally accepted practices here. I will like to point out that just because something is commonly practiced or believed does not make it the best way or even right. Part of the reason I am writing this article is to stir up the hobby and get people to let go of old ideas and keep looking for new methods.
Generally speaking, in Fresh Water Fish Only Systems, the approach is to control nutrients with water changes.
Same Thing in Salt Water Fish only Systems but those people are also willing to use chemical means to remove nutrients from there water to a much lower level than water changes can provide. In Particular they love the use of GFO to remove phosphate. This has Helped a lot to keep aquariums clear of algae. Some of them also use combinations of Skimmers and Activated Carbon to remove organics. The cutting edge is to use Carbon Dosing to remove Nitrates. All these things have really helped us keep our Salt Water Aquariums clear of algae. They also use clean up crews to get the last little bit. Snails and crabs etc. They also use plants sometimes to remove the nutrients.
In Fresh Water Planted tanks people use a very different approach. Instead of focusing on removing algae they focus on healthy plants. When the plants are healthy the algae is usually just barley present if at all. People debate why but it seems to be the case. Some of them load up there water with certain ratios of nutrients while others add tiny daily doses of nutrients and never let them build up. These are the hardest systems to battle algae because you have to provide nutrients to the plant which algae also needs. Plant people will argue for decades over the many planted tank approaches.
In Salt Water Reef (Coral) systems people have traditionally taken a no nutrient approach. They use water changes and various chemical means to strip all the nutrients out. Until recently it was not possible to remove them all the way. Now that it is possible, we found it causes our corals are not healthy if we do that. So we now have to maintain low levels of nutrients to get good coral health, growth, and color. I would like to say that those of you who think Reef tanks are beautiful but you are afraid of the chemistry that it is all the same chemicals from the planted tank hobby. Just different levels and equipment. Don't miss out
Light
Light has long been blamed for algae. On of the first fish stores I ever shopped at way back in 98 had a switch by the counter to control the lights for all the tanks. When a customer walked in, Lights went on. Soon as they left, Lights went off. Also algae eaters were used.
To this day I have had managers at certain Chain Stores tell me that light is the cause. Just turn off the light and you won't have any. That's probably true but why sell me a light I can't use? Don;t worry. I love a bright tank and I have very little algae in all my tanks. I will teach you. For now just know that How bright, How long, and what color (Wavelength) a light is can have an effect. Light does not cause algae any more then any other one factor does. What causes algae is an environment that the algae prefers and light is a part of that. Replacing old bulbs and lowering the amount of daylight hours can help slow algae down. In my experience it has never really solved any of my algae cases. I classify it as a minor factor but I do concede that exposing a tank with nutrients present to daylight, bright light, or long photo periods can cause problems.
Case Study:
I recently talked to a fellow hobbyist who has a lot of experience with breeding. She was using Salt water bulbs over her freshwater tank for years with no problems. The myth is that this should have caused huge algae outbreaks because she was not using the right spectrum. I use those bulbs too because I like a white light vs a yellow light in my tanks. Myth Busted
Flow and substrate.
Some people believe low flow is a contributing factor to algae and have stated that increasing there flow got rid of there algae problem. I have seen similar things. With low flow the fish waste is no longer being suspended in the water long enough for the mechanical filtration to remove it. It settle to the bottom and rots. This releases loads of nutrients into the water. It increases over time until you reach a tipping point where the algae explodes.
Having inadequate pumps can cause this but so does Gravel. I classify low pump speed as a minor factor.
Substrate (Sand and Gravel)
When water flows over a fairly flat bottom such as glass or sand it does not slow down that much. When it flows over rocks or gravel or decorations it has to change directions. It bounces off and looses all it's energy so it slows down and all the waste falls out. I no longer prefer gravel in any of my systems for this reason. Nothing but problems. Also shrimp cannot get down into the gravel to eat the waste but they can turn over sand grains very nicely.
Some substrates can release high levels of iron or phosphate into the water. Some can release higher alkalinity which is a good thing. If your using plain sand or gravel you don't have to worry about this. I
I have had a lot of algae cases because of this property of gravel. Deep gravel is even worse. I classify Gravel as a major factor.
Temp
Something I found out years ago that no one ever talks about is that certain types of algae (mentioned later) prefer warm water. So keeping the temperature higher then you need to is a minor factor in certain cases.
pH and Alkalinity (kH)
pH and Alkalinity (also known as kH) are closely tied together. I am not going to get into that discussion here except to say the more alkalinity the higher and more stable the pH. Many types of green algae seem to die off in more alkaline waters. They seem to prefer acidic or lower pH water. I have heard many people argue bitterly over weather Alkalinity or Nutrients are the main factor of algae. I like my tanks at a higher (but still in safe range for my species) alkalinity. I have few algae problems in any of my tanks. I classify Alkalinity as a major factor (Especially in salt water tanks).
Nutrients (Level and Ratio)
We are now going to start a major discussion about nutrients and how they can lead to algae. This section is very controversial. What is not controversial is that pretty much everyone in the hobby agrees if you have way to many nutrients you will likely have algae problems. Unless you have no light at all. I don't like dim tanks and so I keep mine to the lowest level I can get away with and have healthy pants and corals. If I only have fish I try to strip them out completely.
Also the ratio matters. We have found that certain nutrients should be in a certain ratio. For example a 10 to 1 by ppm ratio for Nitrate to Phosphate. Example would be 10 ppm Nitrate to 1 ppm phosphate or 5 ppm nitrate to 0.5 ppm phosphate. Be aware that a phosphorus test is a little different and you have to multiply it by 3 to get the phosphate amount. We have seen that when this ratio is skewed or when nutrients are way to high that certain types of algae occur much more. I classify Nutrient levels and ratios as a major factor.
Water changes remove nutrients but also may bring them back in if they are in your tap. testing both your tank and your tap water will help you see what is happening. I have seen well water with Ammonia, city water with Phosphate, and have heard reports of nitrate in city water which is pretty bad for your health but attempts to call it in usually get ignored. The reason is most likely fear of legal action. Better just to deny it ever happened.
Next we are going to discuss specific nutrients and how much they contribute. This section is very controversial. I like that First I need to explain there are 2 main types of nutrients int he aquarium. I am going to try hard not to get to scientific. There are chemicals (Compounds) know as organic that have a whole bunch of atoms all in long chains and elaborate shapes. We can't test for them and most algae can't eat them anyways. Some are sitting on the bottom of your tank like uneaten fish food or fish poop. It would seem like they are unimportant but they actually are. The reason is because bacteria do eat them and over time they are broken down into the inorganic form (we will talk about next) which are available. It is like a slow time release of nutrients to the algae and plants over time. In some cases, you may find a tank with a huge algae outbreak but all your nutrient tests say 0. That is because there is a large amount of organics built up in the gravel or dissolved in the water. The algae eats this tiny amount instantly and so there is none left to show up on the test.
Activated carbon and Resins can help and water changes are also very important for this. I like ROX Carbon from Bulk Reef Supply. Some people say Chemipure is using this kind of Carbon along with other things like GFO or Purigen. I also love Purigen from Seachem. It does the same job but each can do a slightly different job. The particle size matters. There is a lot of overlap between these 2 products and some Cichlid keeps I know use both at the same time. I classify organics as a major contributing factor to some kinds of algae.
The next type of nutrient is inorganic and that is the only ones we can usually test for. Think of them as already broken down as much as they can be, dissolved in the water, and chemically active and available for algae, plants, or corals. The amount is important but also the ratio (Usually between Nitrate and phosphate)is important. I classify them as a major contributing factor to most kinds of algae but which one matters to which algae.
Ammonia
I am not going to cover the nitrogen cycle here. It is the price of admission. If you don't understand it go find out now. It is that important.
Like most of you I believed that my tanks never have ammonia because they are already cycled and my test kit shows there is 0 ppm anyways. Tom Barr has done a lot of research on this subject. Unfortunately his original news letters on Algae were lost and are unavailable anymore. he stated he has done experiments where he added ammonia to tank water and got green water. I have also found references to ammonia in scientific literature regarding this.
If a aquarium had no and inadequate bio filtration, or perhaps a bunch of fish were added all at once and the bacteria has not multiplied yet, algae can start to take over as ammonia builds up. What is interesting is that the API test kit may not be sensitive enough to see these trace amounts. Hanna instruments makes Ammonia Checkers now that are much more accurate and can read smaller amounts. I plant to get one some day and continue this research. For now I will say that if you see a system with green water and little biological filtration surface area (Such as bio Media, sponges, or sand) you may be looking at an ammonia issue. It probably effects other types of algae too. Some people say it is what makes a algae spore germinate into a bloom. We will talk about a green water case later on in the green water section. I classify ammonia as a major contributing factor to some kinds of algae and certainly toxic and should be addressed where ever found.
Urea
Urea is something that I never hear come up in aquarium forums at all. Tom Barr wrote an article stating when he added this to a tank he got "Stag Horn" algae. I have seen pictures but I have never had this type of algae in my tank. To add the Urea he added a lot of shrimp and snails from what I remember. Urea is a form if Nitrogen like Ammonia, Nitrite, and Nitrate are. It may show up in these test but I cannot find any info on this. I also see Urea test kits are very expensive and must be refrigerated. I classify this as probably a major factor to some types of algae but we can't test for it so not much can be said for sure.
nitrite
Nitrite is part of the nitrogen cycle and will not be around long in our tanks. In salt water it can lead to certain types of red algae. Julian Sprung has a great book on Salt Water Algae. The only time I ever saw red fuzzy algae was in a salt water fish only tank that was cycling and had high levels of nitrite for weeks. Water changes were not practice at the time. There were no fish at the time so there was no risk. When the nitrite cleared the red fuzzy algae went away too. I classify nitrite as not likely to be a factor for very long if at all.
nitrate
In the old days, when we first got nitrate test kits, it was popular to believe that nitrate was a major factor in algae and we started doing everything we could from water changes to chemicals to control it. It turns out it's probably only a minor factor. I will say that having massive amounts of Nitrate do seem to lead to green hair algae. I will also say if you have a system loaded with nitrate you have a aquarium keeper who doesn't care about there water and so it's loaded with phosphate and probably organics too. Having super high levels of nitrate probably does lead to outbreaks. Having lower levels of nitrate (say between 0 and 20 ppm) will probably have very little effect at all. I thought for a long time how to classify this one. I guess the answer is "It depends". In cases of very high nitrate, say over 40 ppm) it's probably a major contributing factor. In freshwater systems under that it's probably a minor factor but watch your ratio. In salt water systems it seems to be a much bigger contributing factor. However if your levels are under 10 ppm it is probably not your the problem. Systems with undetectable levels of nitrate (and phosphate) are usually pretty spotless but can't support plants or corals.
I will say that it's ratio to phosphate does seem important . if the ratio is skewed one way or the other, various types of algae may appear. More on that in the case studies. The ratio might be a major factor. it depends on how bad it is skewed. A minor imbalance at low levels of nitrate and phosphate is very unlikely to matter.
Nitrate can easily be removed with water changes but probably not all of it. The closer you get to 0 nitrate the more impractical this way becomes. There are also ion exchanges like Purolite which trades Nitrate for salt (only works in fresh water). I don't recommend that one. There are biological media made for it like Seachem's Matrix or Denitrate. You could also use any porous stone like pumice or other ceramic products. These have no negative effects. There is also deep sand beds. In my experience they work for a while then stop. I believe this is due to fish waste build up deep inside them. A new technique is carbon dosing which most people insist is only for salt water because you need a skimmer. That is false. You can use it in fresh water. Water treatment plants do it every day. The issue is that it makes a black bacteria sludge. You have to have a way to take it out or it will break down and add the nitrates right back. My idea would be glass bottom and a power head pointed at it to keep it stirred up. Then use regular filter floss to mechanically remove it from the water. To be honest, it's a pain in freshwater and I would go with the Matrix/Denitrate type solution in fresh water. It does work amazingly well though in salt water. Take your nitrates down to 0 ppm easily. Don;t add too much or you can cause cyano bacteria outbreaks.
In Julian Sprung's book on salt water algae most of the red algae's are associated with too much nitrate and some nitrite. I will say that the advent of Carbon dosing and bio pellets tremendously with algae prevention and control.
A long time ago....
A long time ago, maybe a decade before bio pellets or carbon dosing was a product called Deniballs. It was a carbon dosing product as far as I can tell. I always wondered about it but never bought it. It was expensive and most nitrate management products back then didn't seem to work. We all wished for a nitrate product back then because we got tired of doing massive water changes on our big tanks to try to control nitrate. I realize now the answer was right there the whole time. Props to the inventor of that product. You were way ahead of all of us.
phosphate
This is a super controversial nutrient. It comes into aquariums from the food over time. It can also come in from the tap water. The thing I only recently figured out is that massive amounts of it can come form old rocks such as "Live Rocks" from a polluted system or "Base Rock" (dead coral that came from another aquarium). Often those people had no knowledge of phosphate and let the rock soak it up in water containing 100's of ppm's of phosphate for years. That will defiantly cause algae and headaches but it takes while for it to soak back out into your water again.
In the old days a planted tank system called PMDD came out and said that having phosphate that was too high would cause algae outbreaks. It does. However, people have misinterpreted that to mean any phosphate causes algae. That is not true. However, if you strip out all the phosphate from your fish only system, I highly doubt you will see any algae. We do that mostly with Poly Filter Pads or GFO. Doing that to nitrate may work but is much harder. Doing it to Iron or Potassium will not matter either. I recommend at the very least you have a Phosphate test kit and keep it in the proper ratio with nitrate. If it is a fish only system just strip all the phosphate out with Poly Filter Pads. I promise this will put the hurting on many types of algae. Especially the green ones. If you keep plants you need to have some phosphate.
In Julian Sprung's book on salt water algae most of the green algae's are associated with too much phosphate. I will say that the advent of Phosban reactors and other GFO products helped Tremendously with algae prevention and control.
iron
Iron is equally controversial as phosphate but much easier to deal with. It gets blamed for algae sometimes and especially in farmers wells that have high iron in there water. Iron test kits only test for the one form of iron that plants and algae can use. The good news is that it doesn't stick around long n aquariums where you are not adding it on purpose. It falls right out of the water. No deed to test it unless your adding it for your plants or if you suspect your well water is highly contaminated with iron. If you get rusty stains from your shower head and toilet you might. You could use a chelator like EDTA to fix that. You could also use RO water and mix up your own. That is a whole different subject.
I will say that Iron in massive doses can cause an iron bacteria that looks nasty. I have never seen it in an aquarium.
Planted tank people often add iron. Sometimes with other "Micro ferts" and sometimes by itself. Adding massive doses of iron could cause problems but not likely IMO. They just fall out of the water anyways. Adding the other micro ferts can though. More on that soon. The only time to add Iron is if you have a planted aquarium and I recommend tiny daily doses that set your iron level to 0.1 ppm Iron. I do not recommend dosing weekly.
I was all set to classify Iron as a minor contributor at best if at all. However Planted tanks are notorious for having traces fo algae that will just not go away. Sometimes they have full on outbreaks. Usually it's too much light and/or too much fertilizer (Nutrients) in those cases. There is a tank I have been testing for about 5 months now which had traces of a green stain type algae on rocks in higher light areas as well as well as green spot algae. I tired every level and ratio of nitrate and phosphate I could find anywhere. Nothing. Due to an unrelated issue I recently started dosing tiny amounts of only Iron (no Micro ferts) daily to set th elevel to 0.1 ppm when the lights come on each day. Suddenly the green stain algae vanished from off the rocks and the green spot algae has slowed way way down. Maybe done. I was not expecting that at all. Greg Watson says in his guide that algae is often the result of a deficiency and not a surplus of nutrients. So the story on iron may not be over just yet.
Metals (Micro Ferts)
Metals have been shown to lead to algae blooms in fresh water systems. This is something that has also been heavily studied in the mining and well industries. We are talking about Metals and Heavy Metals which are toxic to fish. I can;t tell you which one causes which algae etc. I can tell you that you don;t want any of them. Examples are Aluminum, copper, manganese, zinc, cobalt, lead, Mercury, Nickle....etc. You can;t test for some of them and if you tried you would spend a lot of time and money. It is impractical. You could send a sample in to Triton Aquatics and see all of them. This is the main reason why we do water changes in our tanks. These metals build up from tap water and fish food and over time become toxic. They also can accumulate from tiny amounts in tap water or from salt mixes. They also can contribute to algae for sure. TO remove them you can use aquatic plants. Certain products remove certain ones. GFO removes Arsenic and Aluminum. Cuprisoarb removes copper. None of them remove it all. Only plants and water changes will do that for you. The hardware store sells heavy metal test but people and fish are different when it comes to toxicity so I don't think it is useful. I classify metals as a major contributing factor.
Silicate (Dissolved Sand)
Silicate is actually a major cause of a specific type of algae known as brown diatom algae. Will talk more about that soon. There are test kits. Don't buy them. Here's why. Weather you have city or well water it will probably be loaded with silicates off the chart. The brown algae comes with every new tank and then goes away on its own or gets eaten by algae eaters. After this happens the silicate levels drop down to non detectable levels and the brown algae usually never returns. You sometimes do get trace amounts inside your tubing if light hits them. It's a non issue. Don't worry about silicate. I classify it as a major but irrelevant contributing factor to Brown Diatom Algae.
spores
Transmutation was disproved a long time ago. People used to believe that rotten meat actually transformed into maggot. Science showed that it was actually flies laying eggs in the meat when no one was looking.
Algae cannot magically appear. It comes from spores just like plants come from seeds or runners. Some of those spores can travel right through the air. Some cannot. They come into your tank on fish,plants,corals, rocks, or decorations that you add. Even used equipment. Using dips might help but most people do not bother. Some of the species of algae like nasty water with lots of nutrients but some grow just fine in "Good" water. They show up in the spores find there way into your system. This probably accounts for those mysterious difficult types of algae such as Black Beard that know one can figure out where it comes from. My advice is that you buy from a dealer who does NOT have algae all over his tanks. I cannot tell you how many times I have seen a old fish keeper with a store with dim lights and yucky algae all over his tanks. Has types of algae I have never had. I bring a fish home from his system and now, 3 weeks later, I have the same thing. be very discriminatory who you buy fish and especially plants or corals from.
germination
Germination (In my non educated terms) is when an algae spore decided to come out of sleeping mode and go into algae bloom mode. Some people believe ammonia causes this. I can't say much else but I wonder of there are other factors.