Thanks so much for responding.
My tank temperature is 78, it is only a ten gallon tank so I have only put 4 bloodfin tetras and two zebra danios in it. I have three small plants and one snail (he rode in accidentally on one of the new plants yesterday). I do 33% water changes weekly and keep the ph at 7.0. I have a waterfall style filter which I was told will keep plenty oxygen in the tank. The rest of the fish in the tank seem to be fine, just the one is ill and his stomach area is starting to look sunken in. I have had the tank for about a year now and have had no deaths as of yet so I don't have a lot of experience to draw on.
I have a bloodfin tetra who seems to be spending a lot of time close to the surface of the water and seems to be "panting", I know I feed too much and thought I was fighting a pack of planaria, but the behavior of this fish has prompted me to get parasite treatment (as recommended by the guy at the pet store). The rest of my fish do not seem to be affected, but this one seems to be losing weight on the bottomside (for lack of a better working knowledge to describe it), and he looks miserable but is not scratching against anything in the tank. HELP!
