It says 10 ppm (mg/L) GH 120 KH 240 pH 7.5 NO2 and 3 barley moved from ND. So it's something with my tank, again. Is it cycling and it just appeared done? Did I kill off the bacteria that brakes everything down? I have two plants and one which looks like a fern with wrinkled and long leafs is growing like mad. I have two rocks, one is a lava rock with tons of little holes and the other is ruff but no real holes. I have sand now for like a month and I used to have shells too but I changed my mind with those and took them out a week ago. I could say that the blue platy may have had what it died from before I got her but the messed up NO 2 and 3 wouldn't have helped. I have have a few tanks before but I've never had this problem before.
There could well be more than one issue playing into this. Let's take one thing at a time.
First, these numbers for nitrite (NO2) and nitrate (NO3). If nitrite really is 10 ppm (which equals 10 mg/l), no fish can live in this. So right away I must question the test results. The inaccuracy of test strips was mentioned back in the thread, though I would not expect it to be this far off. However, you did mention adding salt, and one thing salt does is help with nitrite, so this may have factored in. But nitrite above zero is danger no matter what.
You have not given us test numbers for the tap water alone, not tank water, for nitrite and nitrate. It is important to know if this may be a source, which is possible. When diagnosing trouble you must eliminate all possibles to find the cause.
It sounds like the substrate was changed a week ago, that would have lost bacteria. Was the filter touched at all, either cleaned or media replaced? And you say this tank was initially cycled?
Aside from salt, was any other substance added to this tank for the ich, or anything else?