PH is always creeping up... what to do?

[deeze]

Wow... hey guys, thanks for the replies. I guess no one has any ideas that I can use to fix this? Chem Geek (your user name scares me...ha), my alkalinity is 80ppm and my total hardness is around 400ppm. Had to add another jug of ph down today... errr.

Thanks a million,

[chem geek]

I see that you posted the TA and CH in an earlier post in this thread. Sorry I didn't catch that the first time. So it's not an unusually high TA. You didn't answer about aeration features such as waterfalls, spillovers, fountains, etc. -- do you have any of those running?

Other than the curing or aeration, I don't know what would cause your pH to rise so much. If it's curing, you should notice some rise in CH over time. Exactly what sort of chlorine tablets are you adding -- do you know what kind of chlorine it is (does it say something on the ingredients list like "Trichloro..." or "Cal-Hypo" or anything like that, and if so what does it say)?

Finally, what exactly does the can of pH Increaser say are its ingredients? Does it say "sodium bisulfate"?

Richard

[deeze]

Hey Richard... ah yes I forgot to mention I have two 2 foot waterfalls, one 4 foot waterfall, two deck jets and two locations that have two jacuzzi jets (swim-out in deep end and sun step in shallow end). However, my ozonator does create 100 billion trillion zillion little micro air bubbles in the water... I guess that's how it works to sterilize? I'm not sure. Those little bubbles are sooo prominent I usually have to turn the main pump off about 2 hours before I have friends over to let them all raise to the surface (takes forever because they're so micro small).
My PH Decreaser is made by Aqua Chem and it's 93.2% Sodium Bisulfate and 6.8% "other ingredients"... that's reassuring.
The 3" Slow-Dissolving Sanitizer tablets are also made by Aqua Chem and are 94.05% Trichloro-s-triazinetrione and the rest is other ingredients again. It also says 84.65% Available Chlorine.

I really do appreciate all the time you’re spending with me and this problem Richard... you rock!

[chem geek]

Ahhhhhh! Aeration it is! I didn't consider the ozonator to be doing aeration, but it actually makes sense. It produces ozone which is highly reactive and gets turned into oxygen. With the water saturated with oxygen, the excess will turn into tiny bubbles -- very similar to an SWG except in that case the bubbles are hydrogen gas.

So, using Trichlor tablets for chlorine is a decent thing to do since they are acidic -- it helps in your situation (even though it doesn't help enough). But the Trichlor tabs will keep adding CYA to the pool so you might check on the CYA level to make sure it hasn't gotten really high.

As for solving the pH rise, you can "prove" which area is the worst problem by selectively turning off different features and noting the change in the pH rise. I see three basic groupings of features you can look at: exterior aeration such as the waterfalls, internal aeration from the jets (not regular returns, but jets that include sucking in air so bubbles come out), and the ozonator. If you can turn these three areas off individually, then you can see which, if any, is worse than the others. Then you can maybe put some of the areas on timers so they aren't "on" as long. That's my best suggestion at this point.

You could add Borates to reduce the "rate" of pH rise, BUT you'll still end up adding just as much acid over the same time period -- just doing so less frequently (so instead of a some acid many times it'll be a whole lot of acid fewer times). You (probably) won't get the benefit waterbear and others have seen with using Borates because the algicidal properties will reduce chlorine consumption but that won't have you cut down the ozonator time since it doesn't generate chlorine. So that's why I don't suggest borates for this particular situation. Of course, I could be wrong (wouldn't be the first time!).

Richard