salt and 81ºF is rarely going to "cure" your fish of ich. It my knock it back, but it rarely elinimates it totally from your fish. temps need to get up to 91ºF to kill ick and salt needs to be at a tsp/gallon to kill ich. obviosly temp and salt will work together--but medications on the market will work far more effectively far more uickly.
This is incorrect information. Salt will kill ich, and do so quite nicely at any temperature. Temperatures above 86* F will also kill ich, but it's a bit riskier to count on temp alone. 91*F is largely unnecessary. As a general rule the increases in temp are used to speed up the life cycle and get the ich off of your fish quicker so that it can be killed. Ich cannot be killed while on the fish. it must grow and fall off first. Meds are no faster than salt because you still have to wait for the ich to grow and fall off your fish. the only thing that will speed up the process is the temperature elevations, and that works equally for meds and salt both.
Pictus cats in particular seldom survive meds even at half dosage. Half dosage of most meds is seldom highly effective on ich (usually inneffective and dangerous really). so using meds for sensative fish is really not something I would ever reccomend. If you were dealing with a hardy fish that didn't mind the meds, and you could use full dosage in a clean tank. they are probably O.K., With anything sensative, salt is really the safest method by far. The crux of the matter is salt or meds either one will kill the ich if used properly, but since meds are much more irritating and dangerous it makes no sense whatsoever to use medications for ich.
Remember that whatever you use will need to be kept in place for a good bit of time. Once all ich is gone from your fish you need to continue treatment long enough to kill the ich when it hatches. It is usually reccomended to continue treatment for a week after the last ich cyst is gone. Read the article I linked in the other post for more detail.
If I were a betting man, you'd never get me to bet a pictus can survive full dose meds for more than about 3 days.
BTW you might request one of the Mods combine your double post. double posting seldom if ever helps, and will usually scatter information far and wide and add confusion to your situation.
Dave