+1 ....if you want some advice and see a setup in full swing of hypo ....i have a 300 gal with 38 large tangs, angels, wrasses, triggers, anthias, clowns, and gobies all on 6th week in hypo ....all done in the DT getting ready to move them in a month or so to a new 540 setup......the first three weeks were a touch and go nightmear but at about 2 1/2 weeks things were back to normal and appetites were off the chart and are still like they havent been fed in a week .....I only lost a yellow coris wrasse and one bellus angel who died before the hypo started from ick......and to answer biggar statement above NO the tank doesn't cure itself.....yes they can live with it in the DT but its only a matter of time before one of those little things you are doing keeping it in check goes off just a little and then its epidemic time for the contents.....I was one of those just letting them naturally deal with it and one slight change and BAM it was on like no tomorrow building up numbers and starting to effect fish that were otherwise never showing a sign ....luckily im very passionate about my fish and i was going to do whatever cost or labor it took to WIN and I did ....it took 3 separate 70 gal water changes a day for 10 days to offset the amount of ammonia in the system from all the die off from the hypo....a QT wasn't an option as I have 38 lg fish where would I QT that many fish and what filtration system would house them in hypo ....I had nothing established ....so I let the tank cycle with them in it as I knew it would happen from the die off .....all it would be was a matter of keeping the ammonia in check until the bio could catch back up and now the system has full filtration and its at .09 and everyone is doing wonderful .....no ammonia and NO ICK.....and thank to some reassurance from Bill and Roger I stuck with the course and everything pulled through even though it looked like death warmed over for about a week lol