There was a thread on this before, and I'll say the same. I'm willing to bet that many breeders use something to clean the water, since no one wants to spend the money to buy conditioner for as many fish as they might have. Either that, or he's like me. My water is very safe, and I do not use it any conditioner for any of my fish. I haven't had any deaths (other than euthanasia) since April, and I have 14 happy, healthy, beautiful fish. The circumstance is unknown to us, so we can't really yell or get angry. Odds are his water is safe since his fish are 1) alive, and 2) not bad looking.