Polished "Accent Stones"?

[Purple]

When I got my new fish, my dad (being cheap as usual) didn't want to pay for any of the rocks/gravel/sand at the pet store that we got him. We went to the dollar store and got these "accent stones". They're medium-sized smooth stones.

The problem is that when I was rinsing them before putting them in Donald's tank (2.5 gallon, unheated, unfiltered) it seemed like there was some kind of... stuff on them. I couldn't really feel anything, but the water seemed to just separate on the stones. I scratched the stone and there was a little streak where my nail had been. When I put them in the tank, there were little air bubbles attached to the rocks. You can see them here.

Are they safe? Should I take them out? Is there anything I can do to make them safe? I haven't put them in my female's tank yet. I have no way to test the water.

[thekoimaiden]

I actually use those same stones in my goldfish tank. For the most part, they are safe. But you need to do a test: the vinegar test. Basically you put the stones in a bowl of white vinegar and let them sit for about 5 minutes. If the stones bubble or fizz, they aren't safe to use. If you don't see any bubbles they are good. You also need to look for little veins of iron (they will look red and rusty). Iron in the water is not good for your fish.

If you are worried about the stuff on the rocks (probably some kind of wax) take a clean toothbrush or something with bristles and give the rocks a good scrub. Having your fish in a bare-bottom tank for a few days won't hurt them at all.

[bettafishfinnatic]

yes, just let them settle and they should be just fine

[Purple]

I want to try the vinegar test just to be sure. How do I clean the vinegar off of the rock afterwards? Can I use just one stone?

[thekoimaiden]

I clean the vinegar off by running the stones under water. Rinse them until you don't smell vinegar.

I don't understand what you mean by "use one stone." I try to test multiple stones at one time to make the whole process go faster.

[Purple]

I figured that since they look the same and are from the same company, if one rock works fine then the rest should.

[thekoimaiden]

Not exactly. Not all of the rocks are cut from the same stone. I've had bags where only one or two fizzed, and then I had bags where at least half of the rocks fizzed. You really should test each rock.