I have a 24'x52" Intex metal frame AG. We finally got it up in between constant rain & then it literally rained/stormed every day for almost 3 solid weeks with maybe one dry day 2-3 times. I'm in MO where lots of flooding has taken place. So.....it's finally dried up enough for me to get the pump/filter set up & start filling. I measured & it has just about a foot of rainwater. I got in & the bottom is very slimy feeling although the water is very clear. I haven't added any chemicals. Should I drain off the rainwater & then start filling or can I add to the rainwater? I have well water with no rust or staining, but lots of minerals. And, yes my bad, but I delayed ordering my kit so until mid week all I have is a cheap chlorine/Ph/Bromine from Walmart test kit. Thanks in advance!