Tomcat

I've used muriatic acid (like a teaspoon full at a time) to bring down the ph, but I've never heard of a reaction of it with calcium harness. I do the same with my pool and haven't had any problems.

The test sample was taken before the addition of any chemicals. I tested the water right after taking the sample as well as after letting it sit for an hour to cool off, both times same result; spa - zero calcium hardness. Test kit and chemicals same as previous testing. I tested my pool water with satisfactory results, CH right where it was before for at 275. Therefore two possibilities 1) CH consummed by something, or 2) something else in my spa water messing with the test.

This question is about my spa. I've taken care of my pool for three years now without any problems. In dealing with my pool, the only way to lower calcium hardness was a partial drain and refill. Now to my spa. I started it up about a month ago and got everything in balance. Initial calcium hardness was set to 250. Just did another calcium hardness test and the result was zero! Same test set, same test chemicals, taken one month apart. Where'd my calcium go??? The only thing I can think of is it all calcified in my heater, but is that possible in just one month? Ph and TA all pretty much held in check (although constant adjustments are required - much harder than taking care of a pool). Thanks

No formula, but my experience is it takes very LITTLE muriatic acid to lower ph. I'm talking like a teaspoon for my 500 gal to drop from 8.0 to 7.2.

Sorry if a repeat. I searched and didn't see anything about this. Just wondering if they're any drawbacks to placing unfaced fiberglass insulation around my shell. Seems like an ideal solution - easy to remove for service. The only worry I have is the mention of creating a nice warm den for some critters. Other than that, I guess using the blue stryofoam on the inside of the cabinet is the next best alternative for a DIY? Thanks