Harmful rock?

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KreativJustin

Aquarium Advice Freak
Joined
Jul 9, 2011
Messages
335
Location
North East, Indiana
Hello everybody,

In the past, I've just thrown in rocks after scrubbing them and then boiling them for a half hour and letting them cool down. I've never had an issue with any rocks hurting my fish or tank.

Now I was researching more into it and a lot of people say there are stones not to use and that certain ones are toxic or will dissolve in your tank, and then I read an article which says 95% of the "negative" things are actually rubbish.

So I'm putting about 7 rocks in, I've attached a couple photos, but I want to know your experience, particularly negative ones if any.
 

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All ive ever done is give rock a bit of a wash down and put them in the tank. Boiling can be really hazardous. If there are any air pockets in the rock, excess heat can cause these pockets to expand and the rock can explode.

If the rock is composed of calcium carbonate it will disolve in water, more so if your water is acidic. This will raise your general and carbonate hardness as well as your pH. You can test for this with a few drops of vinegar on your rock and see if it reacts/ fizzes. Whether this would make your rock unsuitable would depend on your water and what you want to keep.

Rock is a natural product and will contain various minerals some of which may be harmful to your fish. Ive heard of slate containing copper deposits that killed invertebrates in the tank.

Your research is probably correct. 95% of the time you will be fine, but there is always that other 5%.
 
All ive ever done is give rock a bit of a wash down and put them in the tank. Boiling can be really hazardous. If there are any air pockets in the rock, excess heat can cause these pockets to expand and the rock can explode.

If the rock is composed of calcium carbonate it will disolve in water, more so if your water is acidic. This will raise your general and carbonate hardness as well as your pH. You can test for this with a few drops of vinegar on your rock and see if it reacts/ fizzes. Whether this would make your rock unsuitable would depend on your water and what you want to keep.

Rock is a natural product and will contain various minerals some of which may be harmful to your fish. Ive heard of slate containing copper deposits that killed invertebrates in the tank.

Your research is probably correct. 95% of the time you will be fine, but there is always that other 5%.

I want to say this with care, because I am obviously asking for opinions and experience. I want to be respectful to you, because I do not think you are wrong or dumb, so take the next sentence without offense please. Everything that you put there in there I've ready articles saying is wrong, besides the part of 95% of the time you will be fine. This is why I am so confused on what is real and what is not real lol. I've always covered the rock when boiling, or put the rock in a container and poured a couple of boiling pans on them and then covered. Never had an issue myself. Just lost in the weeds of whats fact and not fact. Thank you for sharing your experience, its the same experience I've had I believe.

Here's an article I read..

https://aquariumscience.org/index.php/14-3-rocks/
 
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A lot of the hobby is opinion and you will always get differing opinion from different people. A lot is based on peoples personal experience and different people will have different experience even when dealing with the same issues. Facts can be hard come by, especially when the industry is geared towards selling you stuff you dont need and nobody with resources to find the facts are interested in doing so.

What i can say is that calcium carbonate does disolve in water. Thats something that is easily repeatable. Calcium will raise general hardness and the carbonate will raise carbonate hardness and pH and these can be easily measured. It will disolve more in acidic water than basic water. Whether this is harmful or not will be down to individual circumstances.

Copper will kill invertebrates and copper can be found in rocks.

Read through the forum. There are numerous posts of people having health issues with their livestock that has been attributed to substrate, rocks or even artificial decorations. Take things out, things improve. Trial and error returning things to the tank until you find the culprit. Sometimes the things people put in their tanks are the problem.

Ive read through that website you linked years ago. There is some good information in there, and some absolute nonsense. The creater of the website has shown up in various forums and when confronted by people who actually understand the science (that doesnt include me) a lot of what he says doesnt stand up and he moves on somewhere else. He wont even put his name against his claims.

FWIW ive never had a problem, but ive never really experimented. Just get rock from the store and i know what it is and what it does.
 
Thank you for that bit of knowledge, I do appreciate it.

Do you know if my rocks (in the pictures) would be considered risky to put in there? I am no rock expert lol
 
I see you’re from Indiana. In our part of the country, look for granite, slate, petrified wood, but stay away from limestone.
 
Thank you for that bit of knowledge, I do appreciate it.

Do you know if my rocks (in the pictures) would be considered risky to put in there? I am no rock expert lol

If you are worried then do a vinegar test so at least know if the rock is reactive. Those pinkish grey rocks could be limestone (im no rock expert either), which would be calcium carbonate.

Amen to that, a lot of limestone around here.

There you go then. If your area has a lot of limestone then its likely your water supply is hard with a basic pH so even if the rock is calcium carbonate its not likely that it will just disolve away on you. From another thread you was asking about water softeners . I dont know if you went down that route, or some other method of softening the water, but if you did it would seem kind of silly to add calcium carbonate back into water when you have been trying to remove it.
 
I want to say this with care, because I am obviously asking for opinions and experience. I want to be respectful to you, because I do not think you are wrong or dumb, so take the next sentence without offense please. Everything that you put there in there I've ready articles saying is wrong, besides the part of 95% of the time you will be fine. This is why I am so confused on what is real and what is not real lol. I've always covered the rock when boiling, or put the rock in a container and poured a couple of boiling pans on them and then covered. Never had an issue myself. Just lost in the weeds of whats fact and not fact. Thank you for sharing your experience, its the same experience I've had I believe.

Here's an article I read..

https://aquariumscience.org/index.php/14-3-rocks/

Here's the thing, experience is one of the best teachers in this hobby. Some facts apply everywhere, some somewhere and some just don't. A lot of the information on the internet is based on wild animals while most of the animals we keep are domesticated, farm raised ones. They are very different animals in many ways. They don't have the same diseases, respond equally to the same treatments, eat the same foods, breed on the same cycles, the list goes on.
As someone in the fish business with experiences around the world, this I know to be true: Water is not the same everywhere. Because of this, what works for some won't work for others. There are many posts on the internet that are nothing more than a person's limited experience in their part of the world. It may or may not apply to the reader. This is why asking people in your area about the fish you are keeping is a better option than just getting all your information from the internet.

With all that said, Aiken is correct that stones and rocks are easily tested with some vinegar to determine if they are safe for your aquarium. Us looking at pictures is useless because " rock is rock" and it's the chemical makeup of the rock that matters. You can't tell that from a picture.

As for the site you posted, check the reviews of it. I did and was very surprised because I follow .org & .edu sites more than .com sites. Of course some of the opinions posted on the site are 100% correct. Some are very wrong. He never posts the scientific papers behind the claims and some of the chemical science posted there, needed to be and were corrected by actual scientists. So you need to take it all with a grain of salt. I do know that I no longer use that site as a reference site. :whistle:
 
If you are worried then do a vinegar test so at least know if the rock is reactive. Those pinkish grey rocks could be limestone (im no rock expert either), which would be calcium carbonate.



There you go then. If your area has a lot of limestone then its likely your water supply is hard with a basic pH so even if the rock is calcium carbonate its not likely that it will just disolve away on you. From another thread you was asking about water softeners . I dont know if you went down that route, or some other method of softening the water, but if you did it would seem kind of silly to add calcium carbonate back into water when you have been trying to remove it.


I did go down that route and has been installed. I had very little pH change, just the overall hardness went down. I do not want to add any more back to it, you are correct there, I will do the vinegar test and remove any that fail.
 
Here's the thing, experience is one of the best teachers in this hobby... (removed more of the quote for space saving)


Thanks for your advice. The last time I used rocks (6 years ago) I just found some nice shaped ones, cleaned and boiled, and threw them in there without any obvious issues that I could see. Sometimes I like to read into things, and that makes things more hectic rather than helpful lol. I never thought before that a rock chemistry would hurt the fish.

I went from hard water (even for being in city) to softened water recently, only noticing the overall hardness go down. I will do my best to eliminate any limestone and keep my eyes peeled for any water chemistry changes or fish behavioral changes.

Do any of you guys/gals have a trusted resource that you use when trying to find the truth in the weeds, or should I just look for a facebook group for my local area on fish communities so that way I'm more lined up with parameters like mine. I do enjoy AquariumAdvice though, very knowledgeable people. I have never been a huge proponent of just winging it when it comes to the health of something, whether that is good or bad is subjective.
 
I did go down that route and has been installed. I had very little pH change, just the overall hardness went down. I do not want to add any more back to it, you are correct there, I will do the vinegar test and remove any that fail.
There will be no pH change because the softener replaces calcium with sodium, but does nothing to the carbonate side of the equation. This will lower the GH but do nothing to KH and its the KH that effects pH.
 
Right now I use those little test strips, I really need to invest into an API Test Kit (I used to have one when I did saltwater). The pH on the strips shows me as being a little high up there (and kH), so I was hoping for a little drop, but didn't see anything. I don't like to put chem's in my tank, and the fish have been doing great with my current pH, so I've not done much to adjust it.
 
As for the site you posted, check the reviews of it. I did and was very surprised because I follow .org & .edu sites more than .com sites. Of course some of the opinions posted on the site are 100% correct. Some are very wrong. He never posts the scientific papers behind the claims and some of the chemical science posted there, needed to be and were corrected by actual scientists. So you need to take it all with a grain of salt. I do know that I no longer use that site as a reference site. :whistle:

I suspect the author of the site was an active member here 3 or 4 years ago. Either that or he was the sites biggest fanboy. When he was challenged on whether he was the author we never heard from him again.

I did find out the name of the sites author, but i dont remember it. Maybe it was on this forum.

One thing i found particularly annoying is the way he called out products for not working, but didnt test them in the way the manufacturer recommended. Its fine to question things, and test things, and if they dont work call things out. But at least test things properly.
 
I suspect the author of the site was an active member here 3 or 4 years ago. Either that or he was the sites biggest fanboy. When he was challenged on whether he was the author we never heard from him again.

I did find out the name of the sites author, but i dont remember it. Maybe it was on this forum.

One thing i found particularly annoying is the way he called out products for not working, but didnt test them in the way the manufacturer recommended. Its fine to question things, and test things, and if they dont work call things out. But at least test things properly.
Absolutely. You can't expect them work when not used properly. It's like buying a gas powered car and not buying gas for it then saying the car is defective. :facepalm:

That is the problem with the internet imo, anyone can post almost anything on it. :whistle:
To the OP, sometimes it works best to keep fish that fit your water than to try to alter your water to keep a certain fish. Now that your water is softened, you do want to stay away from calcium based decorations as that will only undo whet you did to your water. (y)

As for where to find info, I don't always find Facebook to be the most reliable source. ( I'm in a few groups but just to answer questions and correct false or bad info. ) Once again, a lot of people spout limited information from limited experiences that may not apply to you. You are better off finding local in person fish clubs as they will have more localized info to you. I can message a buddy in Indiana for them if you can't find some on your own. (y)
 
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