PH is not the issue, itafx is new to aquariums I believe and should be careful giving advice. 8 is great for half the species you have, but your fish really aren't compatable because of the differing tank conditions they need. You never did say your tank size.
Dropsy is possibly caused by bacteria, internal infection, virus, or poor water quality. Fish actually can recover from dropsy just fine as long as the kidneys aren't affected. Antibiotics can help with dropsy, maybe antibacterial food as well. Your fish are small unfortunately, if they were goldfish I'd recommend an antibiotic injection. Nonetheless, aggressive antibiotic treatment is going to be you best bet, but heat and salt won't hurt much, raise it slowly so your white clouds (i'd assume) aren't stresses.