Barbs and Rocks

Question
I have a green tiger barb (along with other types) that I would like to partner with an opposite sex mate.  How do I determine the sex of the one I have currently?

Also, I have added some large decorative rocks to my tank.  They were given to me and although they are beautiful, I think they were found, not purchased. Are there any types of rock that should not be used?

Thank you!

Answer
Hi Amy;

There is more you will want to know about breeding barbs, so here is a link to some good info;
http://www.tropicalfishcentre.co.uk/tigerbarbs.htm

The rocks I am cautious with are any that look like limestone, seem "chalky" or anything that seems metallic or "rusty". These can release toxins, raise your pH, or cause water chemistry trouble. Also be wary of rocks that have lots of tiny crevices and/or holes. There could be bugs or dead "critters" in there that can pollute your aquarium as they decay. You can boil them in a pot of water for an hour or so just to be sure they are clean. If the water seems dirty, pour it off and start with a fresh pot to give it another boil. Do this until the water is clear and there is no suspicious residue or organic matter coming from the rocks. Be careful handling boiled rocks! They stay very hot for a long time.

Followups welcome

At Your Service;
Chris Robbins

Come on over and join us on the freshwater fish forum at About.com to get even more information too;
http://freshaquarium.about.com/od/questionsanswers/a/naavigateforum.htm

My member name is ChrisR62. See You There!