the white rock could be corel rock that is used to grow corel on or its the skelington of the dead rock thats ..or it could be just a holiday block thats for feeding ure fish slowly by disolving over two weeks... or it could be lime stone for raising the alkelinity (ive decided to bycot p.h. as i think it sux). or it could just be a rock thats white.
ru u talking about white rock as a decoration or white rock as a filter media? if is filter media then is is Zeolite it function is removing ammonia, if it is a decoration I would need a bit more of a descriptioon that "that white rock" as it is a bit vague
