This thread came to my attention as it is in the wrong section, and after reading your post I'm pretty worried about the health of your fish. From what I have read 50 gallons or 190L is the smallest size tank a discus should be kept it. Along with that they are much happier in groups of 6 or more. Keeping discus in a 127L may cause your fish to stunt in growth, causing many problems. Along with Angels your tank is overstock and also seems to be causing territorial issues. Can you post your stocking please?