I've had great success with quick cure ich meds. High heat and salt works okay too. DO NOT do ich meds with high heat and saly combined!
Treat at half doses (1 drop per 2 gallons @ tank listed water volume... not actual) for three days/treatments and then do a water change, clean mechnical filtration, and start all over again. Ex: Day 1: 50% gravel vac water change, clean mechanical filtration, then half dose of Quck Cure. Day 2: half dose of Quick Cure. Day 3: another half dose of Quick Cure. Day 4: 50% gravel vac waterchange, clean mechanical, then half dose of Quick Cure again like Day 1. Day 5: half dose Quick Cure. Day 6: half dose Quick Cure. Day 7: same as Day 1 and 4. Day 8: half dose Quick Cure. Day 9: another half dose of Quick Cure. Day 10: same as day 1,4, and 7. (get it?) and so on and so on till you see no signs of ick. Then keep doing the treatment cycle for another 10 -14 days. I have killed some pretty resilient ick with this method.