New to pools and struggling. Please HELP!

[jdubh]

So, I bought a 16' x 48' round Bestway pool and finished filling it up Monday night. I then put 1lb of all-in-one shok x-tra in. Tuesday, I checked on it and was very orange/brown looking. Wednesday, I checked again and is has gotten even worse. I checked the filter, and it was pretty orange, so I replaced that. I did add 3 oz of iron myte last night. When I checked this morning, it looked even worse, and I saw some groupings of black stuff. I have browsed this website a bit, but I am just not understanding what is going on. I not sure what my next step should be.

Any help is greatly appreciated.

Thanks

 

[reggiehammond]

Is this from well water or municipal water? Really recommend getting a proper test kit (link below) as test strips are basically "guess strips."

Test Kits Compared
Pool Care Basics

 

[jdubh]

Municipal water. I did bring a sample into my work, and they were able to test a couple things for me.
Free chlorine 2.2 mg/L
Hardness 320
PH 6.9
Dissolved solid total 600 ppm