Pool liner feels like sandpaper

[pleasehelp]

I noticed a previous post about this, but it was an igp, mine is an agp. I have no idea how to deal with it. The pool store gave me some scale prevention, but it really didn't do anything. I don't know if my water is cloudy, or if the scale build up is so heavy that I can't see through it. This is only our second season start up, and I am ready to sell it!
Start up this year has been horrible!

[aylad]

Don't sell it yet. Give us a set of test results, taken with a drop-based kit, and tell us what you have put into the pool (ingredients, not just "shock"). Also, if you can take some pics, send them to poolforum@gmail.com, along with the URL of this thread so Ben will know where to put them.

[pleasehelp]

At 8:00 pm the Chlorine .4, TA seems to be 200, PH 7.7. Where to begin on what we have put in the pool?-We have been through roughly 16 cases of shock, 1 gallon of muriatic acid, 1 container of phosphate remover, 2 treatments of Poolife mustard algae treatment. The liner has felt like sandpaper since we first opened it.
We have a Pentair 1.5hp pump, with a sand filter. Last night I put in 4 gallons of chlorine and this morning it still showed 3.0.

[aylad]

Ok--what is the volume of your pool? what is the ingredient of the "shock", and how much constitutes 1 case? What testing kit are you using? What is your Calcium level?

What you're describing could be calcium scale, or could be sand algae--can you describe what it looks like? What color is it?

[pleasehelp]

It is a 26,000 gallon pool. 1 case is 4 gallons of 12.5% sodium hypochlorite. The testing kit is Poolmaster Basic 5 test kit, uses drops.(plan on buying the kit recommended on this site) The last calcium level was 154, according to the pool store test. I assumed the scale was calcium, from PH being too high? It is white and crusty, just like the feel of medium grit sandpaper. We have had a DE filter, but just couldn't keep up with the clean up, so we switched to a sand filter last week. We also use the FROG system. I will try to get a picture sent in.
I just put in 2 more gallons, really not sure what I am doing at this point. Last year the start up was picture perfect, and the upkeep for the summer was easy. This is only my second year to start up. The one pool store just told me to keep pouring the chlorine in, and backwash the DE filter as often as needed, which was about every 20 minutes. R

[aylad]

Each gallon of 12.5% should raise your FC by approx. 4.8 ppm. In order to attain shock level, you need to know your CYA (see the link to the best guess chlorine chart in my sig for more info and for the chart). If your CYA is 0, then you'll need to reach 12-15 ppm of chlorine in order to achieve shock level. If you have green in the pool, you'll need to reach and maintain shock level until it clears.

Can you break off a piece of the scale? If so, put it in a covered jar with some white vinegar overnight and see if it dissolves. If so, there are folks here on the forum who can instruct you in what's needed to dissolve it back into your pool water, but definitely don't use any cal-hypo for chlorination until that's addressed.