Thanks guys I really appreciate the help! I'll try to answer the sticky as best I can to find out what went wrong.
1. Betta had small chunk of caudal fin affected with fin rot and I immediately started doing water changes, figuring I had caught it in time, the next day it looked like he had been eaten alive with the stuff, has clamped fins, was EXTREMELY lethargic to the point of being unresponsive to me. Which is very unusual for Falcor, he is generally an attention hog
. His swim bladder was also swollen up really bad so he couldn't swim down. He was essentially stuck at the top. But that has pretty much disappeared since I've had him in the hospital. His swelling has gone away now, and no it was not dropsy thank god.
2. I keep my water at 76 F but I cranked it up to 78 F since this started. All of my readings came out zero but this was also after I had already started water changes. The ph stays around 7.6ish.
3. It's a ten gallon that's been running 8 months, never had a problem before. I've got him in a bettaview 1/2 gal that's floating in the main tank. No filter or anything. Got it specifically for QT.
4. A stock HOB filter with medium cartridges(came with tank at yard sale), I've modified it slightly by hanging it higher to get more turbulance, and added two small sponges so I wouldn't have a colony crash while changing the filters, which I've only done twice. I believe in just rinsing in tank water. One week I'll rinse the main filter, the next week I'll rinse the little sponges if they are really gunky.
5. I have a community tank that has been together with no problems for six months, which includes two bamboo shrimp(two in. Each), two bumblebee gobies(neon tetra size), 4 ghost shrimp(1cm ea.), a rubberlip pleco(2in), and an unknown amount of Malaysian trumpet snails,probably close to 100. (I've started picking them out since this started bc I believe they are messing with my bioload, so far I've got about 50 out.With five being close to an inch long.)
6. I do water changes upwards of twice a week. Changing about 20- 30% at a time. Three days before this I actually had to refill the tank about 55-60% since the cat knocked my pwc hose out, and I woke up to half the water gone and on my floor. The intake on the filter was totally out of the water so I had to use an airstone while I refilled it. I'm not sure how long the fish went without it. Possibly a few hours. I vacuum just the main areas about once a week.
7. Six months, all together, no sickness.
8. Just an endless supply of MTS.
9. 4 hikari pellets for the betta, frozen brine shrimp for the gobies, the betta usually hogs part of that so I have to shoo him away(reason for the low amount of pellets). The shrimp clean up the rest of that and then I leave half of a
Spectrum bottom feeder disk every 3-5days for rubberlip and bamboos if they don't get enough out of the Kent microvert drops I put in for them. Which isn't very often since I jiggle the filter for them and they are happy with that. About two weeks ago I started feeding the fish some mosquito larvae that I got from a baby pool I set up specifically for that. I wash them and the bumble bees aren't sick from them so I doubt that's why he got sick.
To be honest, i think what happened is when he just had the one spot of fin rot, and I started doing water changes, I also rinsed the filter out as well. When that happens the water gets really cloudy from the debri right? So I think I basically covered him in bacteria for about ten minutes when I meant to help. From now on I'm going to float him in a cup while I clean to keep him From getting dirty if that idea has any merit.
