Api master liquid test kit Pronto, BGK'S are scaless so meds/salt can make it worse, but you can do kosher salt at half the dosage of 1 teaspoon per gallon of water, raise tank temp slowly to 84-86 degrees (over a day or 2) for 2 weeks, do 2
pwc's a week (10%) gravel vac very thoroughly to get the spores that have fallen off into the gravel so they can't reattach, don't stop treatment when you don't see no more spots do it for the full 2 weeks. After 2 weeks gradually lower the tank back to the normal temp (over a day or 2) and after the temp is back to normal do a bigger
pwc 30%