Like two months ago my girlfriend lost a mix of 11 spotted and figure - 8 puffers. (6 -10 bucks a piece) They were all doing fine, then bit the dust mysteriously. We cleaned her tank top to bottom, including new livesand. We then restarted her tank as a saltwater tank. We bought her a porcupine puffer ($30), and within 3 days it was skinny and all the food we had been feeding it was laying on the substrate. Stupidly thinking, I figured it was her water quality and stuck her fish in my tank. The next day her fish was toast and 2 days after that every fish in my tank was dead. I had 3 perc clowns ($45), copperband butterfly ($40), regal blue tang ($60), lawnmower blenny ($10), false-eye puffer ($25), longhorned cowfish ($45), long tentacle anenome & anenome crab ($60). Not too bad of a loss....but damn it's depressing.