All bettas I get keep dying with dropsy

[sharkboxed]

It’s been a while! But I need help solving this mystery since it’s really bizarre. (TLDR at the end)

So I have platy fish and amano shrimp, and they all thrive and especially the platy fish even multiply (which isn’t that good since they’re 2 brothers and a sister, I used to have 2 more platy girls I bought but they both died suddenly. The 3 platys I originally have are all born directly at home in the tank), but somehow whenever I get betta fish, they don’t last more than a couple of months before getting dropsy and dying. And it’s always the betta fish too!!

The water quality is fine (forgive me for not providing the exact measurements but I can check when I get home), the filter in both tanks are well established, the floater plants even flourish (too much). Yet the bettas all of them die the exact same way; one day their face, particularly above the lips get swollen, then they start bloating, pineconing, then die. I thought it was just because the male bettas were badly bred to I started to get females, which helped a little since they lasted longer than 2 months, but they eventually also died the same exact way. 
the 2 female platy I also bought from the pet store didn’t die from dropsy, only exclusively the bettas do. I’ve also tried treating them before but it just never works. I also want to mention I have 2 tanks, 60L and 54L. I thought at first it was the 54L who had something in there that made them sick so I switched over to the 60L to see if anything would change but no. The exact same death in an entirely different tank. 

I want to solve this since bettas are my favorite fish but I’m not willing to willingly get one every time knowing how they’ll die, and also pay a ton each month for a new one. Ask any questions and I’ll try to answer to the best of my abilities!

TLDR; I have a tank with platy fish and amano shrimp that thrive, but betta fish consistently die within a few months due to dropsy, despite good water quality and well-established tanks. The same issue occurs in both of my tanks (60L and 54L), affecting only bettas, even after switching from male to female bettas. I’m seeking help to solve this mystery as I love bettas but I don't want to keep buying fish that will inevitably die.

[Tony s]

If the rest of your fish are fine, it’s probably a sourcing issue. Bettas from big box stores have gotten sort of fragile. They can develop weird tumors and usually don’t last long. Some do though. If they all die of dropsy, it may be a water quality problem. Mine usually don’t die from that. Just weird other things. If you could get us fresh readings of parameters including temperature, gh, kh, ph that would be great 

 

off topic, if tldr has become a thing, man are we all in trouble.