Please help so I don't mess this up. I just added water to my 10,000 gal above ground vynil pool with a sand filter. What chemicals do I add, how much and in what order? I filled it with well water that is very very hard, the ph of the well water is about 5 and it has a very high iron content. Also finances are tight so if possible please suggest the cheapest options (for example bleach over trichlor). Thank you