I have a vivarium where 4 frogs died within a week. I didn't get fecals done. I couldn't even get samles because it seemed like the only deposits were blood. The condition of the frogs seemed a lot like ones that I've seen die of parasites. When I had this problem before in a small viv I flushed the water with metronidazole and sprayed down all the plants with metro spray. About a month later I got a soil and water sample tested for the little protozoas that were found in the frogs and there was no more so I put new frogs in with no problem. This new tank is a 55 gal. I could do the same thing but I didn't have fecals or necropsies done. This is a very elaborate viv. I really don't want to tear it down. Any suggestions?