From what I've read, the best thing to do in reguards to rocks is, before putting them in the tank, to take a knife or other sharp implement and to scratch the surface a bit then to pour a week acid on it. Vinegar is the most common one available (unless your a chem major or something fun like that). If it fizzes then it's not a good choice for your tanks (fish wise anyway...not sure on plants *shrug*).
As for the wood...if it's a store bought piece and you've had it in the tank for awhile I'd say it's good to go...personally I've collected all my pieces and boil/bake the smaller pieces to steralize then soak, soak, soak, in hot water before putting them in the tanks to release the tannins (and make it sink faster ). I have still noticed some lovely fluffy white growth on a few pieces but have been told that is natural especially when it's a collected piecs. The latest addition is to (dare I say it on this board) an as of now unplanted tank, it's been in for two weeks (still floating after bleach and 3 days hot water ). So far it's still pretty clean as to "growths" but they may still pop up, although I hope they don't as this is one of the tanks I take care of for the office ().
Ok..you ask for advice, and you challenge it? I mean...By saying that the guppies are still ok, you are seeing if you can get away with it. Don't get you...or I missunderstood You really should test the rock before it potentially messes with your tank chemistry.
Fizzing rocks with acid is an indicator of a carbonate type rock. This rock will dump carbonates into your water (KH will shoot up). If you are doing a planted tank, this is not what you want. Certain fish also won't appreciate it. Not sure about guppies though.
No, I was testing it with the feeder guppies. I had never heard of testing with vinegar before. It is in a five gallon tank with 3 feeders from my crayfish tank. I thought that would a good way to test it if it was safe. I've tested driftwood that way before if I really didn't know what kind of wood it was. I've lost a fish yet. I guess I should find out what the KH of my tanks, our tap(well water) and the test tank is at and test everyday to see what the change is.
When you test it with vinegar and it fizzes, does it fizz like crazy or to you have to stare at it forever to see if it fizzes a few bubbles at a time?
Yes, I think Roger is right in using 10% hydrochloric acid (muriatic acid). This is commonly used to etch concrete and probably available at Home Depot. I think I've heard before that vinegar is not strong enough to really provide a reliable test.
Well the only one that it doesn't pass is the fizzing one(I haven't done it). So hydrochloric acid 10%, well, maybe I try the vinegar first and if I have any doubt find some hydrochloric acid.
I think it is a sedimentary rock of some sort because it has an imprint of a leaf on it. Anyone know what rocks usually have fossils in them and if they are safe?
I may just have to wait for spring and go collecting in the mountains near us for different rocks and more driftwood. I'll see if I can find slate or granite because I know those are safe.
Well, I've been looking at the rock closer and I think its maybe sandstone or something like that. I took some pictures of it with my cheapy digital camera, it was still damp, its got some reddish spots that aren't real visible, but it is mainly grey.