Hey guys, My bloodfin tetra definitely isn't at 100%... He's lost almost all the red in his fins for a couple of days now, and tonight when I fed them, he only ingested food and then spat it out. After observing him a little, he seems to swim in place and tip over to one side, then catch himself and continue swimming normally. My other fish seem normal, and his Bloodfin buddy has all his color. Any idea of what could be wrong? I have a hospital tank ready to go if need be, with its filter in my current tank. Water parameters are as such: Temperature- 23.5 degrees C pH- somewhere between 7.4-7.6 (hard to tell sometimes) Ammonia- 0.25 ppm (my tank is cycled, I've never been able to get it below this) Nitrite-0.50 ppm (I performed a 20% water change today and changed one of my two filters - when I checked 3 weeks ago it was at 0) Nitrates-30 ppm (This was at 5 ppm three weeks ago, before adding two new Yamato shrimp) My tank is a 15 Liter with 2 Bloodfin Tetras 1 Zebra Danio 1 Otocinclus catfish (MY WATER WAS PERFECT UNTIL I ADDED): 2 Yamato (Amano) Shrimp UPDATE: I NOW ADDED NUTRAFIN CYCLE TO HELP CONVERT NITRITES TO NITRATES. NOT SURE WHAT TO DO, PLEASE HELP! MY WATER WAS FINE LAST TIME I CHECKED, THREE WEEKS AGO.