I've had two dwarf puffers in a 6 gallon fluval edge. One of them died yesterday - got sucked in the intake. She wasn't eating much the past month and think she grew weak. Parameters were fine, and I did a water change twice a week in this tank using RODI water that I'd treat with Equlibrium, Acid and Alkaline buffer. The remaining dwarf puffer is doing great. While the fluval edge is a great looking tank, I've decided it isn't very practical, especially for messy fish like dwarf puffers. I bought a 10 gallon bare tank. I'm taking the puffer out, then moving everything over. Will this cause cycle issues? I plan on moving all the water, substrate, filter, heater and plants (anubias rooted to dragonstone). I will then add RODI water to fill the remainder of the 10 gallon. I think in a 10 gallon, I may add one or maybe two more female puffers. Is the male going to attack new puffers being introduced to the tank? He never went after the previous female at all - at least when I was observing it. Is 3 too much for a 10 gallon? I've heard varying things on dwarf puffers, the most common being 1 for every 3 gallons - and is the same advice I got at the LFS. Any comments and suggestions are greatly appreciated.