Borates, MA, fresh water and combined chlorine

[rcy]

OK. I did a full test of my water yesterday (including borate level). Everything good, combined chlorine was .2 My combined chlorine has been .2 for about the past five days (I've been testing daily because I'm obsessive) Borates were 36. I added 3 boxes of Mule Team (plus the associated muriatic acid first). Last night I only tested the borate level and it was 46. This morning I did a full test and now I have 0 combined chlorine. The free chlorine level was 2.2 yesterday and is now 2.4. I haven't changed the output on the chlorine generator.

The only thing I did between testing yesterday and today was topped up the pool wth about an 1/2 inch of tap water and added the muriatic acid and the borax.

Where did my combined chlorine go? Can MA get rid of it, or the borates, or the fresh water, or some combination of all three??

 

[JasonLion]

CC is being both constantly created and destroyed. Organic debris that falls into the pool is first broken down into CC and then further broken down into things that are harmless. Having a very low CC reading is quite common. Sometimes, raising FC a little will get rid of it. It is possible that adding borates was just enough to get rid of it. Or maybe it comes and goes and you just hadn't happened to have tested when it was zero before.