i read few books of marine aquarist from the pro an none suggested on the uv cause it may also remove the beneficial bacteria which may cause desaster to ur fully matured tank....i had number of prob on ich especially on blue tangs.....and once on my flame angel...... i did quarantine the blu tang even. maybe crowd? and raising of temp will never work but might effect on the corals which i encountered b4 ........try takin it out and soaked it into ' stressguard' a new product by seachem. i try soakin my ich fish for 15sec in a liter of saltwater with few drops of stressguard. and do it for 5 days and it works!