Shotaling

So I've had this a couple of times before and thought I had it figured out. I occasionally get some guppies with this white cloudy looking fuzz on their bodies. Previously I've treated with salt and had around 50% survival rate after treatment. Looking to find out what this disease is and why I'm seeing it so I can better treat it in the future. Thank you for any help! Water Parameters: pH: 7.6 Nitrates: 5ppm Nitrites: 0ppm GH: ~15 degrees KH: ~10-12 degrees Ammonia: 0ppm Water temp: 78-80F (past 2 weeks to assist with salt treatment, normally 72-25F)

Not overly educated in the nano fish realm yet (only seriously been keeping fish for ~6 months, finally got my own place to do so). Wondering if there are any fish, locally found or online, that could stock a 2.5 gallon shrimp breeding tank. The nano fish I currently have are Celestial Pearl Danios and Pygmy Corydoras. No they are not in this tank I have them in another 29 gallon tank. I'm not personally comfortable putting either of them in this small of a tank unless they are known to be a good stocking option for that size tank (really don't believe they are though). Really just wondering if there are any fish capable of being housed in such a small tank. Current Setup: 2.5 Gallon Tank 1/8th inch gravel substrate, some catappa leaves, clump of java moss, 3 small windelov java ferns attached to 2 1" pvc segments, patch of dwarf hairgrass. Currently stocked with 2 Blue Dream Shrimp (m+f breeding), and 2 horned nerite snails Tank parameters: pH: ~8 TDS: ~500 Temp: 72 F Totally understand if there is no such fish capable of safely being kept in such a small tank. Just looking to liven up my desk aquarium a bit while I wait for more shrimp. And yes I understand some fish will eat the baby shrimp and I am completely fine with that, will make more hiding spaces if it becomes an issue. Also my first post so any extra aquarium info is greatly appreciated. Looking to learn as much as possible about the hobby even if I don't have a personal use for the information! Thank You!