URGENT! 3 Sick Bettas Mystery, Help!

Hello everyone,

I've used this forum in the past so religiously and it's done wonderful things to help me out. Unfortunately, I'm running into some problems with my little buddies and I haven't been able to find much that's helpful to our specific predicament.

I have four betta fish. The oldest is over a year old. I've kept bettas for years and have never run into a single problem until now. Please, they are not suffering from being poorly cared for. They each have 2 and 10 gallon tanks with filtration and aeration. Since they have become sickly, they receive 90-100% water changes at weekly intervals. During cleanings, no chemical products are used only very hot, boiling water and cold water on ornaments, tanks, and gravel. They are fed an alternating diet of freeze dried blood worms, frozen blood worms, betta flakes, and betta pellets. Their tanks are not currently heated due to the summer heat keeping them warm, though they have heaters. I'm sorry I don't have specifics on the water parameters, however, I took samples fro my aquariums in to the local pet store which performed extensive tests that assured me my water parameters were well within a healthy range so PLEASE someone tell me why my babies are getting SICK?!

FISH 1)
The oldest of my bettas is a male, Baby Bruce. He's suffered chronic fin rot. In the past he's been treated with Maracyn and Maracyn Two which seemed to do the trick the first few times. Since, he has consistently been dosed with aquarium salt. The third time, he also presented with protruding eyes, swollen belly, and pine-coning. I assumed it was most likely due to either constipation and or a compromised swim bladder. I fed him less often, and in smaller portions to see if it helped. I also treated him for the pine-coning and swollen eyes with the remaining Maracyn and Maracyn Two I had. I talked to a veterinarian who suggested using a syringe to remove the edema in his chest (fluid if swim bladder issues and or poop if constipation?!) Which I refused. He has since then been getting a little better on his own just by leaving his body to naturally get rid of the waste. Here's the weird part, he makes REALLY big poops every so often. His excrement is round and bulbous, nearly the size of his head! He functions much better not having a hard time swimming and keeping himself from tilting over, as I'm sure any of us would. But in a few days, he just bloats right back up again. I've tried the cooked and skinned pea method with him several times and though he doesn't object to eating his veggies it doesn't do too much to solve the problem of his bloating, and please someone tell me what can be done about his fin rot !? I've heard that the continued use of aquarium salt can be hurtful, though I'm not sure it would be wise to halt its use if it's helping at all to prevent him from getting more fin rot. Additionally and more recently, I've noticed that besides all of these issues taking a toll on him, he's really lethargic. I emptied half the water in his two gallon tank in order to make it easier for him to surface for air. His abdomen seems to have a strange bend in it as well as he struggles to swim. I figured a smaller and more controlled environment would probably be best. I'm not sure if this is due to the lack of fins he's had or yet another symptom of something I have yet to diagnose.

FISH 2)
My second fish, Opal is seeming to develop similar symptoms to the first fish. The only apparent issues so far have been the fin rot, and constipation as well as hiding behind ornaments and significantly less swim activity. I ruled out a dysfunctional swim bladder because I don't believe he's had any balance issues. I've watched him closely and though he does spend significantly more time moping around at the bottom of his tank he isn't having bouncy issues. For the past couple weeks I've been sticking to the aquarium salt, which he's also had pretty consistently for the last few months in order to prevent fin rot. How is it these little guys still get fin rot despite the aquarium salt?! I don't want him to develop similar problems to Bruce, HELP!

FISH 3)
I had never had a single problem with Amethyst until a few months ago. He once during a water change charged out of his container and onto the bathroom floor. (YUCK!) The poor little guy! Lesson learned, always put a lid on the bettas tank. Whatever he picked up on the bathroom floor changed him. Immediately after I scooped him up and plopped him into his fresh tank he was very frazzled. As expected. Just to be safe I treated him for the next week with Maracyn. Besides being scared some scales on his lower abdomen fell off on both sides. It appears that he has bald patches almost on his body. No, they are not sores and they are not growths or Fugus either. The missing scales that fell off simply revealed an almost translucent body, much resembling his color. He used to be rambunctious, swimming all over the place and hyper all the time. Is it just age or did jumping out of the tank permanently change him? It's been a few months and his scales haven't grown back. His fins are constantly clamped and he tries to hide at the bottom of the tank under his decor. I'm really worried about him but I want to be careful not to over medicate any of my fish. Especially if I can't figure out what's wrong with them.

Thanks in advance for any/all responses. I love this forum for always being so significantly helpful!

Cheers!
KissablePenguin