My buddy and I were doing a DIY sump for my recently finished 220. The previos sump had been a 50G Rubbermaid container. Well, all was good until I added some sponges to help grow bacteria. The next morning, my Beautiful Ble Channel Cat and my Shovelnose Cat were dead!!! The next day, I come home, and my 3-year-old Jack Dempsey is dead, too! I called the LFS, had them test my water, and the perameters were nearly perfect. Then we realized, Holy Crap! The sponges did it! The owner of the LFS said that this had happened to her, too. Something on the sponges used to keep them separated during shipping contaminated the water! Yes, before anyone asks, I washed them thoroughly with JUST water. I had to go out of town this weekend, and only my Oscar and Pleco were still alive, and the pleco was sick, too. Oscar was still looking like a champ. I did a binox treatment (pleco was getting a fungus, which he's NEVER had) and I did a large water change. Has anyone else had this happen? I'm devasted! My fiance felt so bad for me that she let my buy myself a baby PacMan frog that I've been wanting for a while for my self birthday present. So, that's a plus. He's awesome. Anyone have any suggestions. I fear what awaits me when I get home.