Downsides to salt pools

[chem geek]

Dave,

My guess is that the white paste is salt. If these mounts were in the deck, then splashed water could go into the mounts and evaporation would get rid of the water leaving the salts that are in the pool. Multiple cycles of water entry and evaporation would leave more and more salt. For an SWG pool, this would mostly be sodium chloride, but there would also be some calcium chloride as well (I assume that the bicarbonate would outgas with evaporation [EDIT] though you could have some solid sodium bicarbonate as well [END-EDIT]) and some sodium cyanurate. The next time this happens, or if the paste is still there, you can test it by putting a little in distilled water (or tap water, if you test the tap water separately) and then 1) see if the paste dissolves in water and 2) measure the salt (chloride) level. If it's high, then the paste is likely to be salt. You could also measure the CYA level to see if I'm right about the sodium cyanurate.

As for what to do, there doesn't seem like much except putting some sort of waterproof caulking around the top of the mount against the stainless steel railing. You could probably very easily remove the caulking when you want to remove the railing at the end of the swim season. I'm not much of a mechnical guy so others would likely have better suggestions.

Richard