Ok so ive had this blue tetra for about 9 weeks now he was one of the originals. My tank is 29 gallons. I jabe a baby platy and full grown platy. Ive got 4 neon glo fish tetra 1 bristle nose pleco and 4 fancy guppies right now. My nitrites and nitrates are within normal my ammonia still hasn't gone down to 0 bit it usually stays at .25 and my ph is a 6. This blue tetra has looked "fat" for several weeks and it doesn't typically act strange he swims and schools and eats and such. Just wondering if I should be worried.