1st post: White hard crystal like deposits on the pool stair steps

[suz15]

Does anyone know what the hard crystal like deposits could be that have formed on my pool steps?
Thanks.

[PoolDoc]

There are several things they could be. In order to make a good guess, we'd need more info, however:

#1 - A set of accurate test results on your pool's pH, TA (CA) alkalinity, and CH calcium hardness. It would be best if you could purchase a K2006, and test it yourself. If you have access to a K2005, that would be fine for THIS purpose (though we don't recommend that kit, because the FAS-DPD test in the K2006 is so important). Test strips, whether you use them or your dealer does, are better than nothing, but not by much.

#2 - Test results from your WATER company. If you ask, they'll send you the most recent full results, or tell you where you can find them on their website. What we'd need are the list of inorganic mineral and metal ions (like chlorides, sulfates, iron, copper, magnesium) but not the biological values, like oxygen demand or the other results like pesticides or radionuclides.

#3 - If you can take a good set of photos, send them to poolforum AT gmail DOT com FULL SIZE.

Other than that, you can do a mini-test, by sprinkling some dry acid on the deposits and seeing whether it affects the deposits or not. Whether they bubble or not IS significant. Even better, if you can scrape off a bit, put it in a glass, add some DISTILLED water (from the bottled water section at Walmart) and some dry acid and then see if there is (a) no effect, (b) bubbling, and/or (c) complete dissolving.