First year with an 18' above ground Intex Ultra Frame. I filled it with well water, and when I shocked it, it turned brown. Metal Out fixed the issue, but I haven't put chlorine back in it since, other than the floating tablet, so the chlorine level is very low or non existent. If I use chlorine free shock, will that still turn it brown due to the iron in my well water? I'd like to get the chlorine back to where it should be so I can then hook up the SWG, but will chlorine free shock work with the SWG?