The only 'solution' for ich is to kill it off before you add a fish. Otherwise it will come back for vengence every time something else goes wrong in your tank. You can use chemicals to do this, but a simple 6 week hyposalinity at 1.009 after a 5 minute freshwater dip will eradicate the vast majority of parasites that come in on your fish. A quarantine tank can cost as little as 1 10 gallon tank, 1 powerhead, 1 sponge air pump, and a handful of PVC pipe segments. The PVC is just to give the fish hiding spots, which reduces stress. Everything should be cleaned between quarantinings. If you happen to get one of the Taiwanese ich variants that can tolerate extremely low salinity, you might have to resort to copper to kill it off. Cleaner shrimp and gobies don't eat ich or marine velvet in the wild. They might eat it in a tank, but don't make that your sole defense. (Don't get cleaner wrasses at all. The ocean needs them.)
Otherwise, you will face the choice of catching fish to save inverts, using chemicals in your display tank with myriad potential side effects, or re-treating frequently enough over time that the quarantine will seem like less of a hassel. If you have a near perfect set of conditions, ich and other parasites may never become much more than an irritant, but it seems easier to me to not place all my eggs in that basket.
If you want to clear a tank of ich and velvet, take all fish out of the tank for 6 weeks and keep all the fish in hospital tanks. When they are completely cured, you can put them back into a tank free of the most common parasites.
