Calcium deposits or sand algae

[malfar]

First time in over 20 years and I have white gritty deposits all over the bottom of my vinyl liner. 16x32 above ground with a 7 foot deepend. Trying to figure out how to get them off.

Thanks

[waterbear]

Welcome to the fourm!
It's much easier to answer your questions, when we know something about your pool. We often 'waste' the first few posts back and forth collecting information. So, please complete our new Pool Chart form -- it takes about 30 seconds, but will save much more than that.

Pool Chart Entry Form (https://docs.google.com/spreadsheet/viewform?formkey=dHBLTzdpX19DZVlzUTRLOTU5ZFlZSWc6M Q)
Pool Chart Results (https://docs.google.com/spreadsheet/ccc?key=0Ahjo2iDF0aJgdHBLTzdpX19DZVlzUTRLOTU5ZFlZS Wc)


Also, we are going to need GOOD water test results with a problem such as yours.
Having a good test kit makes pool care easier for EVERYONE. A good test kit means a kit that can test chlorine from 0 - 25 ppm, pH, alkalinity, calcium hardness, and stabilizer with reasonable accuracy. Test strips (AKA 'guess-strips' ) do NOT meet this standard. Some pool store testing is accurate; most is not. The ONLY way you'll know whether your pool store is accurate or bogus, is by testing accurately your own self. On the other hand, pool store 'computer' dosing recommendations are NEVER trustworthy -- ignore them. They are designed to sell more chemicals than you need, and WILL cause many pool problems.

If you don't already have one you should get a Taylor K-2006 (http://www.poolforum.com/pf2/showthread.php?14994-How-to-Get-the-Right-Testkits-for-your-Pool) test kit. It will give us the info we need to help you solve your problem.

[PoolDoc]

Meanwhile:

1. Lower your pH as far as you safely can -- near 7.0 (but not below) is ideal.

2. If you can get a small sample of the scale, leave it overnight in a couple of tablespoons of white vinegar in a Saran wrap covered glass. See if it dissolves. If it does, you've pretty much confirmed calcium.

3. And then . . . get good test results!