Ok I have one pufferfish that is now suddenly refusing to eat. This is not the first time I have kept puffers, and they die under mysterious circumstances. It is kept in a 25 gallon brackish tank about 1.012 salinity. There are also 2 little mono sebaes with it. My Ph is about 7.6, the temperature is 80 F, there is no ammonia or nitrites. I change the water by 50% weekly as many websites have said. I feed the puffer bloodworms, plankton, brine shrimp and snails so his teeth don't over grow. His tank has a lot of hiding places. Right now he spends his time swimming up and down the side of the tank. is there anything big I'm missing. He's about 2 inches and his name is Razzle Dazzle. Btw he has absolutely no grey belly so that's a good sign. What is wrong with it?