Just lately I have noticed my fish flipping, flashing and jumping, I have tested my water for Amononia, Nitrite, PH, Oxygen which are all spot on apart from Nitrate which is very high, well over 100mg/l, So I netted my Shusui which does flips etc the most and underneath I noticed its veins were reddened, apart from that, there is no other visual remarks apart from it been really fat, it normally eats very well, had it for 3 years from 6". it aint been eating since