I moved my powder blue Gourami from his 60 gallon tank to the 20 gallon tank about a week ago because he was being really aggressive with the dwarf Gourami. He is now in a 20g tank with 3 African dwarf frogs, 6 male endlers, and 1 Dalmatian Molly. He developed this blister over night and it just broke. I can’t seem to figure out what it is. Lymphocystis? I have a photo here of the blister and two minutes later after it broke. Any thoughts?