Does crystal kill fish?

Question

I've been told that if you put a real crystal inside a fish tank, that it would kill the fish. Is this true?

Answer 1

Depends on what you mean by "crystal".

Crystal (leaded glass) won't (quickly) kill your fish. A trace amount of lead will leach out eventually, particularly if your pH drops below 7, but I doubt that the fish will care.

If you mean crystals that were grown as part of a toy/project, those are made of water-soluble salts. Most of those salts will redissolve and may kill your fish (some species are pretty tough).

If you mean crystal minerals (limestone with mica, etc.), then I'd look at the advice above even though some minerals are very insoluble and you essentially have the equivalent of a dead coral reef or rock ledge inside the tank (no problem).

HTH

Answer 2

unlikely but could depend upon the crystal. Some could have toxic heavy metals. Check with a local fish supply store to be sure.

Answer 3

depends on what type of crystal. lots have lead in them which will leach out and kill the fish. check the contents then go talk to fish store people.