Trouble getting CC to zero.

[chem geek]

Your TA is a little on the high side which can lead to a tendency of your pH to rise, though you seem to find it pretty stable. The next time you find your pH too low on opening, if your TA is high then instead of adding Borax, do aeration instead. That will cause the pH to rise with no change in TA. Though Borax doesn't add any carbonates, it will have the TA rise when it makes the pH rise (because they go together). It is only aeration that actually removes carbonates from the pool via carbon dioxide outgassing.

I wouldn't worry too much about the rising pH in SWG pools since keeping the TA low and using Borates does seem to help a lot. Yes, you probably will need to add acid more frequently than you do now, but it won't be as often as with most SWG pools where people don't know about the low TA and use of Borates. Check out the various threads on rising pH in SWG pools to see people's experiences and how much acid they need to add. It might be tolerable for you.

Anyway, it sounds like you've got a pretty nice and easy situation currently, except for dealing with iron in your fill water. You might consider using a water softener filter for the water -- you might even have one already for your house. Also, if you use a pool cover (such as the solar cover you mention), then that will significantly cut down your loss of chlorine during the day, will keep your pool warm at night and I'll bet that it's use is why you don't see much of a pH rise even with the higher TA.

As for BioGuard Mineral Springs, the "Beginnings" added at startup is just salt (sodium chloride), Boron salt (i.e. borates), and acid (inorganic and organic). The "Renewal" is just the same thing but with less salt and more Boron salt (borates) and inorganic acid and a little aluminum salt. In California, the Beginnings is just salt with a small amount of Cyanuric Acid (CYA) while in Renewal there is no Boron salt (borates) in the product and instead there is sodium bisulfate (acid). This dry acid adds sulfates to your water and high levels can cause problems, particularly with plaster (but we don't know exactly how high so generally just try avoiding adding too many sulfates) and I don't know if there are any issues with sulfates and vinyl pools (probably not). We do know that high levels of chloride and sulfates together are corrosive to stainless steel (especially with high chlorine levels).

The only thing in the product that helps with the rise in pH is the Boron Salt (borates). The products still add acid (at least partly to neutralize the borate that is alkaline) that is probably sodium bisulfate even outside of California (what is called "inorganic acid"). California identifies boric acid as a hazardous waste so that's probably why it's not put into the BioGuard products sold in California (it probably requires special labeling and/or handling requirements). If BioGuard were really on the ball, they would recommend a low TA setting with their system. I can't find their MS-10 or MS-20 product manual so don't know what TA they recommend.

You can check the price of the BioGuard Mineral Springs and compare it to the equivalent of adding Borax and dry acid (and salt) that you could purchase separately.

Richard