to setup this QT it requires to be fully cycled aswell correct? and does it require a light? ive also ready online the paracite cant survive past 2 weeks specially if its the temp is 78+ to speed the life cycle no?
No, as nereefpat notes, the QT doesn't have to be cycled and doesn't need a light. The basics are heat and flow. The heat's obvious, and the flow can be an airstone, a small wavemaker pump (an inexpensive hydor would do), or a small HOB filter like the Fluval Aquaclear.
And also as nereefpat notes, it's a long conversation. Here's the summary -
1) Treatment for ich can take the form of tank transfer, chelated copper, or hyposalinity. All have their own procedures.
2) Hyposalinity can be used in cycled tank, so it's probably the least stress on the fish and the reefer, since virtually nothing needs intervention except for precisely measuring the specific gravity of the QT and setting up the ATO. There are some ich strains that are suspected of being able to survive hyposalinity, but they are apparently not common - I've certainly never encountered them.
3) Tank transfer is the surest, no-ifs-ands-buts-or-maybes cure for the fish without exposing them to the possible toxic effects of therapeutic copper. It also takes the most work by the reefer, as the fish need to be transferred after every 3 days, and ammonia must be carefully managed.
4) Chelated copper is very effective, but it's best used in a bare tank because rockwork or gravel can absorb the copper. And you must have an accurate copper test kit - too much will kill the fish in a rapid manner. And certain fish won't tolerate copper.
Personally, if the fish is badly affected, hyposalinity would be my choice hands-down, since ich typically infests the gills and compromises the fish's respiration. Because the oxygen level in low salinity water is considerably higher than in normal seawater, the fish is immediately able to get oxygen in a hyposaline environment, and presuming you remove a few rocks and/or cycled gravel to the QT, there's no ammonia to further stress the fish. And the hyposaline environment will rapidly kill the parasites on the fish; when I've done it on an infected fish, all cysts were gone within 24 hours.
I'd use Tank Transfer on newly-acquired fish that otherwise appear healthy and are eating well as a preventative measure, since there are aspects of the procedure that puts stress on the fish (transfer to a "new" tank every 3 days, and some amount of unavoidable ammonia buildup).
