Organisms I cant get rid of in tank

Question
I have these betta fish awhile back and have been fighting this organism in the tank for months. Now, after reading one of your articles, I see one of my fish has swim bladder failure. this could be due to either the organism in the tank, or the stresses I have caused my fish trying to get rid of the organisms. the tank at this time is 2.5 gallons, and has two bettas separated by a divider. ONe is male, the other female. However, this organism infected my 10 gallon tank as well. It is visible to the naked eye. they first start out with what looks like hundreds of little white specks swimming on top of the water. then one morning it seems you wake up and there are thousands. they swim very quickly. I have read that they could be some kind of protozoa, and have tried methylene-blue, aquarisol, clear-ick, cleaning the tank frequently. it seems these bettas keep hanging on, but it is obvious that they have suffered as a result, especially the male. He has bouts of difficulty breathing, and now has swim -bladder failure. What could these things be? I never imagined getting a couple bettas would turn into this battle. As far as ammonia levels,and nitrite levels, I guess I need to go buy a kit. these are my first fish. I can send a picture of the thing by the way. i have an image taken under a microscope. I think the are around 150 micrometers. I also have been keeping the tank at at least 75 degrees, have a filter too - both carbon and one that removes larger particles. Please help! Sometimes I want to give up. It has litterally been since november of last year. and, there are times where the little things appear to be gone, or almost gone, and suddenly they are back.
p.s. I am also afraid of adding different chemicals at once because I fear making some deadly mixture (for example methylene-blue and aquarisol.)

Answer
Hi Therese;

Don't bother with the organisms. They aren't harming your fish. I get them in my 55 gallon when I overfeed. They feed on excess nutrients in the water. Cut back on food and change 50% of the tank water once a week and they will disappear. Maybe not completely, but they will reduce. Medicines don't kill them, just starvation. Also be sure to wipe the edges and crevices of the top of the tank at least once a week. Some of these little critters live there and then swim back into the tank. They tend to congregate on my driftwood that becomes exposed when the water evaporates a bit.  

The poor sick fish may have a swim bladder problem. There are many possible causes for it. Here is more info about that;

http://groups.msn.com/TheBettaObsession/illnessamptreatmentpart2.msnw

I hope he feels better soon.....

At Your Service;
Chris Robbins