Calcium deposits on pool tile above the water line

[cliveleach]

Earlier this year I had my concrete deck covered with pavers and the coping stones around the pool are fixed with some type of mortar. What I beleive may be some form of calcium deposits have appeared beneath the coping stones on the tile which is between 12 inches and 20 inches above the water line. Today I have powerwashed the tiles and have successfully removed some of these white marks but others still remain. How do I remove these unsightly stains and should I seal the coping stones and if so what type of product should I use?

[PoolDoc]

I'm not sure anyone here has definitive experience solving problems like yours.

Possibly if you can provide some additional information, someone here can help:
1. Accurate test results on both pool AND fill water. (test kit links below)
2. Summary of your pool environment (complete the Pool Chart Entry Form)
3. Photos of the scale (post with Picasa, Photobucket, etc OR email to poolforum@gmail.com )

Ben

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+ Get a cheap OTO (yellow drops) / phenol test kit, or if available at YOUR Walmart (check availability), get the HTH 6-way DROPS test kit, which is compatible with the Taylor K2006. Test the pool as soon and you can, and post the results. If you get the 6-way kit, ALSO test the water you FILL the pool with, especially if it's a well, and post THOSE results as well. (The HTH is the best available kit you're likely to find locally, but it's not the K-2006. It can only provide rough measurements chlorine levels above 5 ppm, and it measures "TOTAL" hardness, rather than "CALCIUM" hardness, which is not ideal.)

+ 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.

+ We recommend the Taylor K-2006 test kit, which meets the requirements above, for many reasons. The HTH 6-way drops kit is a great starter kit, and is compatible with the K2006 (it's made by Taylor). There are a few alternatives; for example Lamotte makes an FAS-DPD kit that's OK -- but it costs 3x as much. But, we're not aware of any test that is better, and since we are all familiar with the K-2006 (and can help you with it) we recommend it exclusively ( Test kit info page )

One caution for the 2012 season: Amazon does not stock the kits directly. So when buying at Amazon, Amato is our current preferred seller. However, they often don't list enough stock to last the whole day, so try order mid-morning. You should expect a delivered cost under $60 for the K2006A and under $95 for the K2006C. If you can't find that, wait a day.

+ Here are links to the kits we recommend (you can check local availability on the HTH kit, using the Walmart link):

HTH 6-Way Test Kit @ Walmart
Taylor K2006A (3/4 oz bottles) @ Amazon
Taylor K2006C (2 oz bottles) @ Amazon