Hi again...I have a 120ltr tank...the discus looks very normal to me except for its fat gut. He/she justs sits under a log and stares at the others...doesn't attemp to eat at all and I haven't seen it pecking on the bottom for left overs. I hear so many suggestions for water changes. The guy I bought them off said just a little bit off the top every week. someone else said only 50% once a week. I'm told they don't like water changes and so being nervous I opted for a 10ltr freshup every 2nd day...if Im working and don't get the chance then sometimes its on a 3rd day...but mostly every 2nd day. I've kept the temp at 28c because I have 4 corys in the same tank and was told they don't like high temp. Trying to please all of them by keeping it at 28c. I'll try and send a photo ... but the fish's stool is not hanging out now its gone. Actually I've just had another good look at the fish and I think its more pale in colour and the tips of the fins dorsal and back have turned black in colour. I don't think it was that black before. My water is a light tea colour because I have logs in the tank and peatmoss buried under the gravel The ph is about 6.2 and when I add new water I use prime. That rids the water of chlorine, ammonia and nitrates.
Your advice if I've done all the wrong things... I would appreciate your help to get it right.
firstly i think your tank is too small long term for these fish but you can sort this later.
secondly you have been given the wrong advice about water changes. with discus as long as you change the water with water of the same temp and ph you cant give them too much. i think if youn increase the frequency of water changes to 50% daily until the fish shows improvement that would help. but dont just start that straight away, ease into it so it aint a big shock.
can i ask the size in inches of these fish? if they are still small they need feeding upto 4-5 times a day (hence the water changes to keep nitrates down).
oh and prime is good but it only converts ammonia to a non toxic ammonium and doesnt affect nitrate at all.
like i said before i dont think you fish shows signs of worms/parasites. it sounds more like an internal bacteria problem. try load a photo so we can have a few more eyes look at it.