HI Ive not long set my tank up and have just put my first lot of fish in, a clown pleco, 3 glass catfish, 1 upside down catfish, 1 male japenese fighter fish and a giant african fan shrimp, all of them seem to be settling in well and so did the shrimp, it seemed to be quite happy exploring the tank before I left then when I got back its been lay on its side, still moving but can't seem to get back up right? Ive checked the water, temperature is 24 degrees C, ph is 7.8, 0ppm ammonia 0ppm nitrite and 5.0 nitrate. that's good isn't it? can anyone give me any ideas what it could be and what I do to help it??