My Poor Clown Fish

[Robbie2013]

Ok,
I have done some research into the tank transfer method..... I am leaning towards getting the stuff and doing that. I have a couple of questions

1. My regal tang is showing signs of ich and my clownfish are doing what I described above. I als have my dwarf angel and goby who look and are acting fine. Should I pull all fish? Or just the tang? Or the tang and clownfish?
2. How big of a tank would I need?
3. Everything I have read on the TTM talked about moving fish over and letting the parasite fall off. Should I combined it with a freshwater bath, or copper, or hypo salinity, or should I just use the salt water and keep moving them?

I am currently trying Hikari’s Ich-X for reef tanks. Its formaldehyde based and it clams it will not harm invertebrates or coral. Has anyone had any experience with this? I only started last night so I don’t know how fast or well it will work, it tells me to continue the treatment 4 days after the signs are all gone.... presumably because of the life cycle of the parasites. The only knock I have agents it so far is that I need to treat the tank everyday and do a 20% water change every day.... probably for 7 or 8 days. In my tank that will work out to 160 gallons of water and about $150 worth of salt.

Thanks for your recommendations!