Ive just started out in the hobbie and its taken over my life already. I have a 26 gallon (uk) tropical tank with 4 guppies 4 mollies (2 silver 2 black) 10 neon tetra and a gourmie (not sure which type). Have had the tank up and running for just over 2 months and have lost 1 dwarf gourmie and 1 guppy. I have another smaller tank (about 20 liter) what I am using as a quarantine tank. In the smaller tank I had 10 tetra and a seimese fighter. The fighter has been in there 2 weeks and is staying in there but the tetra have been in there since the weekend. 1 died the day they went in there and I joticed it only had 1 eye!!! Ive got home from work today to find only 8 left!!! And one of these only has one eye!!! Is this normal for teteas or could it be something to do with the fighter fish I have in there?