DROPSY???

[Jaded_Pulse]

hi everyone, got a big problem!! a couple of weeks ago my albino kribensis died of a mystery illness, and this morning i woke up to find my scissortail rassbora really sick lying on the bottom. his tail was a bit ragged but i'm almost 100% sure it wasn't my other fish because when my krib was real sick they didn't attack her & they never pick on each other and i hadn't seen any of them near him at all, so i think it was my snail who tried to eat my krib when she died it wasn't white or red on the edges & it appeared overnight so i'm fairly sure it's not finrot. i had to go out but seeing as there was nothing i could do for him i fed the others (who all seem fine), did a quick small water change, and hurried out and back. well he was dead when i got back i didn't often see him eating but i figured he picked at stuff off the bottom & he was swimming around happily right up till when i went to bed.

Tank: 60L
Maintainance: weekly waterchanges approx 25-30%, weekly gravel vac.
Tankmates: 2 male guppies, 1 neon tetra, 1 marble angelfish, 1 columbian tetra, 1 blackskirt tetra

i just went back in and my red guppy & columbian tetra r looking fat.....but my scissortail didn't - do u think it's dropsy?? OMG I HATE THIS think i'm gonna cry lol sorry anyways thanx heaps for all ur help with my krib a couple weeks ago.