Vinyl liner pool. 17,000 gal. Salt water. Intel Chlor. Last weekend pool was almost clear. Took sample in and was told to add a few things including "shock". I have never used shock before (always shocked with bleach), but for some reason this time I used it (urggg). Woke up the next day and the pool looked terrible. Now this week we have noticed the sides about 3 inches past the waterline has a rough feeling to it. Almost like a fine sandpaper. I took a sample in today and was told my water was great. It is light green, not clear. I can see the bottom in the shallow end and I can see the drains at the deep end, but very hazy. I have turned the pump back on (had it on for 48+ hours) and felt like it was doing nothing, so I turned off). Got in the pool today, cleaned the sides with a rag, vacuumed the pool, backwashed, rinsed, added more water and have the pump going and the salt cell going at 40%. My readings at the pool place are:
CYA 42
Tot Chlorine 3.3
Free Chlorine 2.8
pH 7.5
Tat. Alkalinity 117
Adj Total Alk 104
Tot. Hardness 106
Salt 4100
Pool Company is saying I need Scale Inhibitor (several bags at 25.00/bag). Any idea on other things I can do?