SWG - ph always normal?

[tphaggerty]

Have only been operating mine for several months (2 last year, 1 so far this year). I haven't had PH issues, but I wonder if that has anything to do with the rain in the NE being very acidic (which it is!).

[nater]

I'm in the same boat. I've been using my autopilot since March, and my pH has been constant at 7.4 since then. I'm interested to know what you guys have done chemistry wise, as I think my Borax addition is really buffering my water.

In March before the SWC startup I had some algae and CYA over 150 ppm and pH at or below 6.8, and low alkalinity.

I did several partial drains to bring CYA down to 90-100, dumped lots of bleach in until the algae was clear, and used baking soda to bring my alk up to 100-120 and pH up to around 7.0, then used Borax to get to 7.4. In all, I added about 16 lbs of borax, and I think I've got 30-40 ppm residual. I maintain a 6-8 ppm FC residual, with no CC since installation.

I haven't added anything but salt since March, even after a few top offs from evaparation and the pH never budges off 7.4.

Do you have vinyl, gunite, etc???