I got my first fish (betta) late this last winter. Since then that betta died, four shrimp, and my current betta has what I believe to be dropsy (bloated, raised scales... currently have him in a salt bath in clean water and covered but from what I've heard it's not very curable.)
I have a filtered (it has zeolite in it, which works wonderfully but makes it difficult to cycle. I've had no readings of ammonia/nitrite/nitrate) and heated 5.5 gallon tank with plants (java moss and anubis). The temperature hits a constant 74 F (well, except now where I've raised the temperature to low 80's) I use Prime on all my water changes, where I do about an 80% water change at least every week, sometimes more if the fish are loosing color or showing other signs of stress (particularly this betta, he's black and red but will turn transparent at the slightest sign of stress.) The fish were all at separate times (the shrimp were between the two bettas). Whenever I check the levels the ammonia is 0 the nitrite is 0 and the nitrate is 0. (I've never had it show above 20 ppm) Between each pet I've cleaned everything in very, very hot water, certain pieces in light bleach. This current betta has lived just over a month in my care. The shrimp died in about a week. The first betta survived about 2 weeks.
Stress seems to be constant with both bettas. The first betta I put in a 1 gallon, realized that wasn't okay and bought a 5.5 gallon. Then he got the filter. So I thought stress killed the first betta.
The shrimp died so fast I decided it was probably poor acclimation. I've heard shrimp were sensitive- but I did it much like I did with a betta (let it sit, ad some water from the tank, let it sit, scoop out and place in tank w/o water from old tank) However, this is when I put the plants in. I intended to have a planted shrimp aquarium. However, way too disappointing.
This last betta had to survive a move from the dorms and into my apt. However, I thought he was doing alright. I left for 3 days and came back to him being so sick. I changed the water before I left. (and the fact he hadn't eaten in 3 days is what makes me sure he wasn't just bloated)
If he dies I'm not very sure I want another fish, but I loved all the fish I've had. But I feel like a perpetual fish killer. I don't want to have to put another fish through death for my own company. I just don't know what more I can do for them. I don't want to stress them out too much, especially since I think the first betta died of stress...
(Note: it's midnight here, my room is spinning, and this is a VERY long post. I apologize- posting it anyways)