More Test Results!

[chem geek]

Is it possible that my pH just wants to stay at 7.8? When I add acid, it will lower the pH for a couple of days, but then it migrates back to 7.8. Should I even worry about adding acid if it stays at this number?

Alk 90
Cal 350
Cya 50

I noticed that you have significant waterfall features and these contribute a lot to aeration of your water. Also, you have an SWCG system and that also contributes to aeration through the tiny hydrogen gas bubbles it produces (you might only be able to see them at night if you shine a light in your pool).

It is certainly possible that your signficant aeration is contributing to your tendency to rise in pH. Also, your pool is new and though it is Pebble Sheen, I believe that is just rock plus cement so the cement will likely be curing and this will tend to make your pH rise. Eventually, over the next months and probably stopping within 6 months to 1 year, this curing will be complete. However, the significant aeration in your pool will likely still have you fight a rise in pH.

Check back in with this forum after 6 months or so when the curing should have slowed down signficantly and if you are still experiencing a pH rise, then we may have some more advice for you regarding lowering TA and/or using Borates for your pool (obviously check in with us before then on other issues -- we'd love to hear from you!). The low TA and borates are a couple of experiments some users are doing currently and so far appears to be very positive, but since your pool is new and still curing I would wait a bit before doing anything experimental except turning off your water features (waterfalls) and seeing if that slows down the pH rise.

Congratulations on your new pool -- the pictures look great!

Richard

[EDIT] P.S. I agree with Janet (who wrote her post while I was writing mine) that there is nothing wrong with keeping your pH at 7.8 [END-EDIT]

[Simmons99]

We have a new pool as well and ours tends to want to sit around 7.8-8.2. We were told by the pool builder that a salt pool increases the chance of scale - I don't know if that is true - but for our warranty we need to keep the PH between 7.2-7.4. I add about 1/2 gallon of acid a week to keep it within the range.

[chem geek]

We were told by the pool builder that a salt pool increases the chance of scale - I don't know if that is true - but for our warranty we need to keep the PH between 7.2-7.4.

A salt pool is actually more corrosive and less likely to scale than a non-salt pool, all else equal (though the difference between the two is not large). However, an SWCG pool (which you have) tends to increase in pH and it is true that higher pH increases the liklihood of scaling (all else equal) so perhaps that is what he is talking about. In any event, for the normal ranges you are talking about, I think he is being overly conservative (as well as wrong about salt and scaling), but a warranty is a warranty so you've got to follow its requirements, at least until the warranty runs out.

Richard