I've gone through Ich a few times, 2 times in my 95 Gal Flat back hex and 1 time in my 150gal 6' long.
I freaked out and tried meds 1st time and it beat me.... Killed my butterfly and angel
2nd time i tried heat and hypo, all my damsels died, i was left with an Emperor angel and my majestic angel. They started to look much better after about 45-50 days of hypo and heat. Once i thought all was good i started raising the salt and bring the temp down. After all that my emperor never fully recovered and started fading. Never got an actual diagnosis on it. I then upgraded to the 150gal, boiled all my rocks, bought new rocks new sand, let the new tank cycle etc.... did all to avoid it in the new tank.
Put the Emp in a DT and tried treating him with Para shield, for internal parasites... he didnt make it.
My last fish left was the majestic, she is an adult and recovered fully from that last out break.
New tank was up and running for some time with her in it and I began stocking slowly.
I had bought 2 Wyoming White clowns and they claimed their spot in the tank.
I then bought 2 baby hippo tangs after that and the female clown who was already bullying the smaller Clown started bullying the tangs as well. With some time 1 tang held her own, the other got stressed and started hiding... Sure enough Ich came out again in my new tank.
I read a post here about ich and just leaving it be especially with Tangs... So i decided Fluff it, I will let it be and see how it plays out.
I pointed my heads towards all the dead spots in the tanks, my made caves, and made sure there was a good flow to all spots in the tank that any parasites could rest and hatch and cycle over etc...
Anyway, that 1 tang died and 100% sure my majestic and the other tang had it too but they eat very well and didnt hide and ich went away.
Been at least 7 months since that happened.
Now I have a powder blue, a purple tang, a blue face angel, 2 Nearly naked clowns, lawnmower blenny, yellow gobie, my original 2 wyoming whites and my original Majestic Angel from the other tank.
If it happened again i would go that same route... a lot of flow in all areas and make sure all fish are fed well and eat