well that night i read this i did a 50% water change then i went out and bought malefix treatment as well as a rena xp4 with an already running fx5 on there so i am doing the treatment for 7 days and then doing the water change.
I have test stripes all the levels are completely normal no ammonia etc. all the other fish are fine eating well and growing. i will continue the treatment and water changes untill he shows signs of improving. At the moment he is in a 180gallon 6x2x2 so that should be good enough.