New aquarium proposal, thoughts?

[fishtonic1]

Hi all,

I am planning on purchasing a used fish tank: 50L / 13.5g (56cmL x 26cmW x 35cmH).

The fish I was planning on getting:
- 1 honey dwarf gourami
- 10 small tetras or dwarf rasboras
- 6 pygmy corydoras

Is this overstocking? Any help, advice, or thoughts are appreciated.

 

[Aiken Drum]

Seems fine to me. I would say lightly stocked.

Not sure what your overall knowledge about keeping fish is. Here is a link to useful articles about keeping fish for newcomers. Pay particular interest to the ones about the nitrogen cycle and cycling new aquariums.

Articles to Help you Get Started with your Aquarium

Here are a few good resources to help you get started. Tips and Tricks For Your Fastest Fishless Cycle! – Aquarium Advice https://www.aquariumadvice.com/articles/the-almost-complete-guide-and-faq-to-fishless-cycling/...

www.aquariumadvice.com

 

[fishtonic1]

Seems fine to me. I would say lightly stocked.

Not sure what your overall knowledge about keeping fish is. Here is a link to useful articles about keeping fish for newcomers. Pay particular interest to the ones about the nitrogen cycle and cycling new aquariums.

Articles to Help you Get Started with your Aquarium

Here are a few good resources to help you get started. Tips and Tricks For Your Fastest Fishless Cycle! – Aquarium Advice https://www.aquariumadvice.com/articles/the-almost-complete-guide-and-faq-to-fishless-cycling/...

www.aquariumadvice.com

Thanks, aiken.

So you are saying i could add more fish?

 

[Aiken Drum]

Long term, yes. Your tank could accommodate some more fish.

Short term. Go back to understanding the nitrogen cycle and cycling the tank. If the tank isnt cycled yet adding the fish you put into aqadvisor is way to many for an uncycled tank. If you already have your fish and your parameters have been consistent for a couple of weeks, no reason why you couldnt push that aqadviser % up to 100%. So maybe 4 or 5 more of the smaller fish.

Have you cycled the aquarium? If so how?

If you already have your fish, how long has the tank been set up? What are your water parameters? pH, ammonia, nitrite and nitrate preferably taken before your regular water change?

 

[fishtonic1]

Long term, yes. Your tank could accommodate some more fish.

Short term. Go back to understanding the nitrogen cycle and cycling the tank. If the tank isnt cycled yet adding the fish you put into aqadvisor is way to many for an uncycled tank. If you already have your fish and your parameters have been consistent for a couple of weeks, no reason why you couldnt push that aqadviser % up to 100%. So maybe 4 or 5 more of the smaller fish.

Have you cycled the aquarium? If so how?

If you already have your fish, how long has the tank been set up? What are your water parameters? pH, ammonia, nitrite and nitrate preferably taken before your regular water change?

I don't have the fish or even the tank yet. But when I do, i was planning on doing a fishless cycle until all the parameters were in check, then i was going to add most likely the gourami first and monitor the levels for a week, then add one of the schools, monitor levels etc.

 

[Aiken Drum]

The problem with your plan is that the microbes responsible for the nitrogen cycle grow and die off depending on the amount of food available. So you cycle your tank, add the gourami, the microbes will then die off to a level that can be supported from the waste of the single gourami. You then add your school of fish, which is a big jump on bioload, and you could start to see ammonia and/ or nitrite in your test again until your cycle catches up again.

One of the advantages of a fishless cycle (if done properly) is you can pretty much go for a large stock as soon as you finish cycling. I wouldnt advocate fully stocking straight off, but i would probably add your tetras/ rasbora first, then the gourami, then your corys. That way your cycle wont die off so much because the school will have a bigger bioload than the gourami, and it wont need to catch up so much because the jump between the school to the school + gourami is less than the jump from the gourami to the gourami + school. If that makes sense.

Here is my guide to fishless cycle in case you havent seen a proper method.

Fishless Cycle Guide using Ammonia

STAGE 1 – SET UP AND PREPARATION. Set up the aquarium, stand, filtration, lighting, heater if required and any other equipment. Fill the tank and run for 24 hours to ensure there are no leaks and that all the equipment functions correctly. Drain the tank. Aquascape including substrate...

www.aquariumadvice.com

I would also say as you havent got your aquarium yet, is a small aquarium right for you? Despite logic saying otherwise, bigger is easier, especially for new hobbyists. Water quality is easier to manage with a larger volume. Any mistakes get diluted out more in a bigger larger volume too. Consider what space you have, what your budget is etc. If 10 gallons is right for you, then thats great. But if your budget and space allows for a bigger tank, and there are no other issues, its easier to go bigger from the start than upgrade later.

 

[fishtonic1]

The problem with your plan is that the microbes responsible for the nitrogen cycle grow and die off depending on the amount of food available. So you cycle your tank, add the gourami, the microbes will then die off to a level that can be supported from the waste of the single gourami. You then add your school of fish, which is a big jump on bioload, and you could start to see ammonia and/ or nitrite in your test again until your cycle catches up again.

One of the advantages of a fishless cycle (if done properly) is you can pretty much go for a large stock as soon as you finish cycling. I wouldnt advocate fully stocking straight off, but i would probably add your tetras/ rasbora first, then the gourami, then your corys. That way your cycle wont die off so much because the school will have a bigger bioload than the gourami, and it wont need to catch up so much because the jump between the school to the school + gourami is less than the jump from the gourami to the gourami + school. If that makes sense.

Here is my guide to fishless cycle in case you havent seen a proper method.

Fishless Cycle Guide using Ammonia

STAGE 1 – SET UP AND PREPARATION. Set up the aquarium, stand, filtration, lighting, heater if required and any other equipment. Fill the tank and run for 24 hours to ensure there are no leaks and that all the equipment functions correctly. Drain the tank. Aquascape including substrate...

www.aquariumadvice.com

I would also say as you havent got your aquarium yet, is a small aquarium right for you? Despite logic saying otherwise, bigger is easier, especially for new hobbyists. Water quality is easier to manage with a larger volume. Any mistakes get diluted out more in a bigger larger volume too. Consider what space you have, what your budget is etc. If 10 gallons is right for you, then thats great. But if your budget and space allows for a bigger tank, and there are no other issues, its easier to go bigger from the start than upgrade later.

Right, was aware of the nitrogen cycle but wasn't sure how to do it exactly, thanks for the guide.

You say after a successful fishless cycle I could go for a large stock straight away. Does this imply they all get added on, say, the same day but at different times?

And are you implying the entire fishless cycle is done without substrate, decorations etc and done at 28°C?

Also I know its probably opinionated but you say the tank would be lightly stocked, and others say it's too many fish for the tank. I keep getting mixed results unfortunately. But you seem to know what you're talking about. I really want to start an aquarium but unfortunately I don't think I can go bigger than this tank.

 

[Aiken Drum]

Aqadvisor is generally considered to be considerate in its estimations. You can go beyond what it considers to be 100% stocked if you keep up with water changes. Yes its opinionated. Some people will tell you that you are overstocked, some people will say you can put way more fish in there (and i agree you would probably get away with it). My opinion is you have a little scope to go with a few more fish if you wish. Thats backed up by aqadvisor, which is a useful tool to make sure you don't do anything stupid.

While it has limitations, another metric is 1" of fish for every 1 gallon of water. If you say the corys and rasboras are 10" total and the honey gourami is 2", that gives a little room for maneuvre. You generally want 600mm length of tank for small fast swimming fish, the fish you have selected would be fine with the 500mm in the tank you are considering.

When i say there are limitations to 1"/ 1 gallon, what that is, is that 10 x 1" fish might be fine in a 10g tank, but 1 x 10" fish wouldn't. 1"/ 1g doesnt take account of swimming space either. A standard 15 gallon/ 60 litre tank is 24" long and would suit those small fast swimming fish, but a 15 gallon high is only 20" long and be less suited. When you are considering small, narrow bodied fish and also consider the actual dimensions of the tank, 1"/ 1g will prevent you overstocking a tank.

If you complete a fishless cycle you are cycling out 2ppm of ammonia in 24 hours. Thats way more ammonia than a tank full of fish will produce. You can in theory fully stock an aquarium the day after you complete your cycle. As a new hobbyist i would still add all your fish over a couple of weeks though.

For info, expect a fishless cycle to take a couple of months to complete.

 

[fishtonic1]

Okay, so I should do a fishless cycle for around a month / until all parameters are in check (just double checking, during this period, temp should be 28°C? Even if fish need say 26°C?)

And when fish are ready to be added, wait maybe 5 days whilst monitoring parameters, then add gourami, wait another 5 days, then add corys. All while performing weekly water changes.

 

[Aiken Drum]

No. You should do a fishless cycle until you can dose 2ppm of ammonia and see it cycle out in 24 hours. It might take a week, it might take 4 months. It will probably be somewhere in the middle.

Yes. Raise the temperature to 28c. Return it to whatever your fish require before adding your fish.

No, dont wait 5 days after you complete your cycling process. Add fish when your fishless cycle is complete. If you are being cautious you might want to continue dosing ammonia for a few days after the cycle is complete to make sure its well established. But those microbes will start to die off due to lack of food (ammonia) once you stop dosing ammonia. If you wait 5 days after stopping dosing ammonia to add fish your cycle will start to die back.

 

[fishtonic1]

No. You should do a fishless cycle until you can dose 2ppm of ammonia and see it cycle out in 24 hours. It might take a week, it might take 4 months. It will probably be somewhere in the middle.

Yes. Raise the temperature to 28c. Return it to whatever your fish require before adding your fish.

No, dont wait 5 days after you complete your cycling process. Add fish when your fishless cycle is complete. If you are being cautious you might want to continue dosing ammonia for a few days after the cycle is complete to make sure its well established. But those microbes will start to die off due to lack of food (ammonia) once you stop dosing ammonia. If you wait 5 days after stopping dosing ammonia to add fish your cycle will start to die back.

Sorry i didn't word that correctly. I meant after adding the rasboras right after the cycle is complete, wait maybe 5 days before adding the gourami

 

[Aiken Drum]

Yeah. Leave it 5 days, test your water, if you are seeing zero ammonia and nitrite then do a water change and get your gourami. If you are seeing some ammonia and/ or nitrite then do a water change and see how things are in another 5 days.

 

[fishtonic1]

Okay, thank you so much Aiken, you've been very helpful

 

[Aiken Drum]

And just to add to the opinionated bit.

The amount of fish you can keep in a aquarium is largely down to bioload, which is the amount of waste all your fish produce. More fish equals more bioload. Messier fish equals more bioload.

The nitrogen cycle takes that waste (ammonia) and turns it into nitrate. In most aquariums that nitrate stays in the water until you remove it with your water change.

The amount of nitrate fish can toletate is a matter of opinion. An upper figure of 40ppm of nitrate is commonly quoted, 20ppm is more commonly given nowadays, some people will say 10ppm or even lower. Many people keep fish just fine at higher nitrate levels than 40ppm. What you are prepared to accept is something you will have to decide for yourself, but lower is better for fish. Nitrate is toxic, just less toxic than ammonia and nitrite. And some fish are able tolerate more nitrate than others.

What we can say is that if you are doing a 50% water change every week, and you arent able to keep your nitrate below whatever figure you have decided is safe then you are overstocked and should consider reducing the number of fish or moving them to a bigger aquarium. What will tend to happen is that people will put however many fish they want to keep in an aquarium, and if they look at what their water parameters are, thats what they decide they are happy to accept for as long as they dont observe any problems.

A tool like aqadvisor has a built in upper limit for nitrate, i dont know what number they use but its probably around 20ppm. They make an assessment on how much bioload each species of fish has. Does a bit of a calculation and gives you a water change schedule. At somewhere around 30% weekly water change it says you are fully stocked. That's why people say its conservative because you can change 50% of the water and keep your nitrate levels lower than a 30% water change would achieve. Or in planted tanks, the plants will take up some nitrate and aqadvisor makes no allowance for planted tanks. Aqadvisor also gives you some guidance on fish compatibility as well as filter capacity. My understanding is that the functioning of the site is regularly updated as they gather and plug in more information behind the scenes. Its a useful tool, but not infallible.

I tend to look at the water change schedule it gives rather than the estimated stock %. Im happy doing a weekly 50% water change, so if it says thats sufficient im good with that regardless of what stock % it says im at. If you want less water maintenance and only want to do 25% water change every 2 weeks, then thats the figure you should be looking at from aqadvisor. Or you may decide that your aquarium looks overcrowded when its stocked fully. You dont necessarily need loads of fish for an attactive aquarium. I think this is my most attractive aquarium, its 57 litres, and is quite lightly stocked with guppies, a honey gourami and shrimp. I decided the aquascape and planting was going to be the centrepiece rather than the fish.

 

[fishtonic1]

And just to add to the opinionated bit.

The amount of fish you can keep in a aquarium is largely down to bioload, which is the amount of waste all your fish produce. More fish equals more bioload. Messier fish equals more bioload.

The nitrogen cycle takes that waste (ammonia) and turns it into nitrate. In most aquariums that nitrate stays in the water until you remove it with your water change.

The amount of nitrate fish can toletate is a matter of opinion. An upper figure of 40ppm of nitrate is commonly quoted, 20ppm is more commonly given nowadays, some people will say 10ppm or even lower. Many people keep fish just fine at higher nitrate levels than 40ppm. What you are prepared to accept is something you will have to decide for yourself, but lower is better for fish. Nitrate is toxic, just less toxic than ammonia and nitrite. And some fish are able tolerate more nitrate than others.

What we can say is that if you are doing a 50% water change every week, and you arent able to keep your nitrate below whatever figure you have decided is safe then you are overstocked and should consider reducing the number of fish or moving them to a bigger aquarium. What will tend to happen is that people will put however many fish they want to keep in an aquarium, and if they look at what their water parameters are, thats what they decide they are happy to accept for as long as they dont observe any problems.

A tool like aqadvisor has a built in upper limit for nitrate, i dont know what number they use but its probably around 20ppm. They make an assessment on how much bioload each species of fish has. Does a bit of a calculation and gives you a water change schedule. At somewhere around 30% weekly water change it says you are fully stocked. That's why people say its conservative because you can change 50% of the water and keep your nitrate levels lower than a 30% water change would achieve. Or in planted tanks, the plants will take up some nitrate and aqadvisor makes no allowance for planted tanks. Aqadvisor also gives you some guidance on fish compatibility as well as filter capacity. My understanding is that the functioning of the site is regularly updated as they gather and plug in more information behind the scenes. Its a useful tool, but not infallible.

I tend to look at the water change schedule it gives rather than the estimated stock %. Im happy doing a weekly 50% water change, so if it says thats sufficient im good with that regardless of what stock % it says im at. If you want less water maintenance and only want to do 25% water change every 2 weeks, then thats the figure you should be looking at from aqadvisor. Or you may decide that your aquarium looks overcrowded when its stocked fully. You dont necessarily need loads of fish for an attactive aquarium. I think this is my most attractive aquarium, its 57 litres, and is quite lightly stocked with guppies, a honey gourami and shrimp. I decided the aquascape and planting was going to be the centrepiece rather than the fish.

View attachment 390311

Wow that's a lovely tank and fish you have

If I put everything into AQadvisor, it recommends these parameters:



If needed, i'm happy to do 50% water changes weekly. I was going to get a 250/lph filter. (apparently it should filter your tank 4-5 times per hour).
I was going to get some live plants and other softscape/hardscape as well.
Those guppies look nice, i might consider them over the rasboras. How many do you have and what are their genders? If i got, say, 3 guppies, would 3 female be okay as i don't want any breeding?

 

[Aiken Drum]

That kind of equates with what i said about aqadvisor. 24% water change is 87% stocked. 30% water change would be 100% stocked. You could double the number of fish and it would say 50% water change and say something like 150% stocked, which many people (myself included) would be happy with.

Filter ratings are given in ideal circumstances. So 250l/hr will be with no filter media, minumum head difference etc. So in real life you won't achieve their rating and could lose half of what it says it will achieve. So you should oversize the filter by some margin. If a filter is rated for say 20 to 60 litres aquarium, its more suited to the 20 litres end of the range. It will probably work ar the higher end but might struggle if you have a lot of fish and you might get 3x water turnover rather than the 4 to 5x turnover you expect.

Ive probably got about 8 guppies. Im not really into counting fish. They are all male. Guppies are livebearers and livebearers are prolific breeders and can quickly over populate aquariums. So unless you have a plan to deal with lots of guppy babies then go all male. Even if you went all female so there are no males to breed with they are probably already pregnant when you buy them, and some of the babies are bound to be males and they don't care if they breed with parents or sisters.

We have a member who got guppies for a 6.5g tank. They was warned to get only males, but didnt. When the inevitable happened they got a 40g tank to move the guppies to with a plan to sell the excess. Within months that was over populated as well and nobody wanted the excess fish.

 

[fishtonic1]

That kind of equates with what i said about aqadvisor. 24% water change is 87% stocked. 30% water change would be 100% stocked. You could double the number of fish and it would say 50% water change and say something like 150% stocked, which many people (myself included) would be happy with.

Filter ratings are given in ideal circumstances. So 250l/hr will be with no filter media, minumum head difference etc. So in real life you won't achieve their rating and could lose half of what it says it will achieve. So you should oversize the filter by some margin. If a filter is rated for say 20 to 60 litres aquarium, its more suited to the 20 litres end of the range. It will probably work ar the higher end but might struggle if you have a lot of fish and you might get 3x water turnover rather than the 4 to 5x turnover you expect.

Ive probably got about 8 guppies. Im not really into counting fish. They are all male. Guppies are livebearers and livebearers are prolific breeders and can quickly over populate aquariums. So unless you have a plan to deal with lots of guppy babies then go all male. Even if you went all female so there are no males to breed with they are probably already pregnant when you buy them, and some of the babies are bound to be males and they don't care if they breed with parents or sisters.

We have a member who got guppies for a 6.5g tank. They was warned to get only males, but didnt. When the inevitable happened they got a 40g tank to move the guppies to with a plan to sell the excess. Within months that was over populated as well and nobody wanted the excess fish.

Hmm, I see. I really don't want any fry, so I'll avoid M+F / F+F. But that being said, I don't want any aggression in the tank, and i've heard that all males could take a turn for the worse. Do you have any signs of aggression with yours? Probably not as much as if you had 3. You reckon 3 males would be ok?

 

[Aiken Drum]

Male guppies will generally only be aggressive when competing for females. With no females thats not generally an issue. All fish will establish some kind of pecking order and that may mean some aggression until thats established, and some fish are just jerks no matter what you do. Bigger groups of fish tend to spread out any aggression between all the fish rather than just direct it at a single individual which can happen in small groups.

You can never rule out aggression when you are keeping fish. Even with what you are planning, your honey gourami may be an overly aggressive individual, or your group of rasboras may be prone to fin nipping the gourami even though thats not typical of the species. You never know whats going to happen, just have an expectation of whats likely and then deal with any unforeseen issues if they occur.

In a 13g tank i wouldnt mix too many species. Id stick with either the rasboras or guppies as middle of the tank species, the gourami will probably spend time at the top, and the corys at the substrate.

 

[fishtonic1]

Male guppies will generally only be aggressive when competing for females. With no females thats not generally an issue. All fish will establish some kind of pecking order and that may mean some aggression until thats established, and some fish are just jerks no matter what you do. Bigger groups of fish tend to spread out any aggression between all the fish rather than just direct it at a single individual which can happen in small groups.

You can never rule out aggression when you are keeping fish. Even with what you are planning, your honey gourami may be an overly aggressive individual, or your group of rasboras may be prone to fin nipping the gourami even though thats not typical of the species. You never know whats going to happen, just have an expectation of whats likely and then deal with any unforeseen issues if they occur.

In a 13g tank i wouldnt mix too many species. Id stick with either the rasboras or guppies as middle of the tank species, the gourami will probably spend time at the top, and the corys at the substrate.

I see I see. I think ill get 3 male guppies instead of the rasbora school. Sounds like a plan. I'll let you know how it all goes! Again, thanks for your help, i appreciate it as a newbie