Can you use fossils in your tank and how do I test?


Hello, How do I test if something is going to effect my tank? I don't have a air stone or air pump is it necessary or could I just use a container by itself and let it sit a few days?

I'm wondering if different fossilized things I have will be ok in my aquarium? Like dinosaur bones and pieces, other fossilized bones, shells, shark teeth, petrified/fossil wood and that sort of thing. I know there is a possibility of PH rising with seashells and what not...I have recent sea shells Iv thought about testing too. Iv read they can leach calcium in the water as well, is that true? Would that be so bad as I was thinking of getting some snails and that sounds like it might be good for them but maybe not?

If I used shark teeth I would only use larger smoother ones or pieces so no one gets injured by a sharp shark tooth!


It depends entirely on the fossil.
Different fossils may have different minerals in them that could have varying effects on your tank.
If they're in something like limestone, you'll have an increase in hardness. This is easy to test for. Just put a couple of drops of vinegar on the piece and hold it up to your ear. If you hear fizzing, it's basic, and will raise your pH.
Other things are harder to test for, but are also much less common. There is a slI'm chance that something else might show up and harm your fish. Unless you can afford to pay a geologist to analyze the mineral content in each stone you're thinking about, it's up to you to decide whether or not you want to take that chance.

Sea shells will raise your pH and calcium levels. This provides advantages and disadvantages. Snails and other shell-building creatures love the boost. Soft-water fish (like many tetras) would do better without (though, as my tank is testament to, they will survive in hard, high pH water.)


Excellent answer!! Fossils from different areas are fossilized in different ways. Some even have metals in them as pyrite...bad!
If you are finding your own..ask other collectors in the area, what is the matrix they are in.
  • Thread Starter


Thanks guys! I live in FL so Iv been finding fossilized things all my life and in my dads work he runs into loads....I don't know any other collectors though...Are there any ways of sealing/coating things with something to make them safer for aquariums?? I haven't heard of anything yet so there prob isn't anything fish safe but one can hope! About a geologist Id have to ask my dad if he knows any that would be willing to help.

*I would have loved to added some things but the critters care comes first! At least I can add my stones.

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