OK. Kinda new to the whole aquarium thing. Got into it because my 3 year old wanted "fishies" which means I take care of them. Did a lot of research and thought I had a good base until the last week. Have had 2 glofish die in a week. And here is a bit of information about the tank. 10 Gal Tank Been up and running 2 months 1 month ago added 5 neon tetras and 3 ghost shrimp ((down to 2 ghost shrimp)) When I added the new fish ((with much advise I made sure to test water (API frewshwater master) before adding anything new)) PH: ~7 Amonia: 0 Nitrite: 0 Nitrate ~30 Neons are just fine. About a week ago I added 5 glofish (standard Zebra danio type) But have had 2 glofish die for no apparent reason. Now have one I can't tell if it's fin rot or another fish nipping at it's fin. The fish in the image did not have this frayed fin this morning when we fed them about 7 hours ago. Only noticed because since the 2 fish died I have been doing daily water tests just to make sure I'm not misreading any one day, and last few days have been using both the master kit and the API test strips and have the SeaChem Ammonia Alert since I like having verification that the test is correct. Current Paramters: PH: ~7 Amonia: 0 Nitrite: ~0.25 Nitrate ~20 Any ideas on possible death reasons or if this is fin rot or nipping ((I have already started melafix just in case it's fin rot)) Any help or thoughts would be appreciated.