Rising Ph

[gold1]

Hello all, new member and fairly new pool owner here. First let me give you a quick breakdown, pool completed beginning of June, started by following the builders directions of loading the chlorinator with 10 3in tabs and just checking ch and ph with basic kit he gave me. Within 2 1/2 months my CYA was at 60 from the test at a pool store……I know, but he is someone I know and trust in just the testing. Lurked around here for a few months and started following your guidelines. Switched to bleach, added salt and a tiny bit of borate just to start. Used a Taylor drop kit at home just monitoring ch, ph, and alk. Already ordered the k-2006 and waiting on it. Pool looks awesome, crystal clear, which was definitively a result of adding ZeoFibre and great feeling. Latest test results are…
FAC-6
TAC-6
CC-0.2
CH-350
CYA-50
TA-100
pH-7.5
salt-1900
borate 5

Only problem I encounter is having to add muriatic acid daily because of rising ph daily. I have tried at a TA of 80 and 90 but still had the problem, raised it back between 100-110 as the pebble manufacturer recommends. Is this simply from a still new pool? any help is appreciated. Oh, by the way, the ozonator and Nature 2 were installed by the builder even though we didn't pay for it. I use the mineral pack and all the metals testing have been fine and the ozone thing is running just for giggles, not that I think it does much.

 

[HouTex]

Your pool is still new so rising pH can be expected. It rises throughout the first year and maybe into the second year.

You can lower your TA to help with the pH, but it may be contrary to terms of your plaster warranty. I know I keep mine lower than what WetEdge recommends.

 

[JVTrain]

Welcome to TFP!

Looks like your levels are pretty good. pH will rise normally due to aeration. Aeration comes from many sources. Return jets breaking the surface, waterfalls, deck jets, swimmers splashing, rain. Anything that disturbs the surface of the water. Salt water chlorine generators also contribute quite a bit of aeration. I would say that ozonators do as well.

All that considered, your builder is recommending a TA level that is higher than is recommended here at TFP. 70-90 is what is recommended. The reason pH rises with aeration is that carbon dioxide is outgassed from the pool water. Carbon dioxide is acidic when dissolved in water so losing that carbon dioxide causes pH to rise. Total alkalinity is in balance with this outgassing. Higher TA will lead to faster pH rise. Lower TA will have less pH rise due to aeration. However, if TA gets too low, pH can be erratic or easily shifted too low when adding acid. Every time you add acid, TA will go down. I would recommend a few things:

1- Allow your TA to drop to 70 and see how the pH lives. With your current levels plugged into Pool Math your CSI or calcite saturation index is about 0.1, which is great. If you drop TA down to 70 your CSI is -0.1 which is also great. No risk of damage to your plaster either way. But, with the lower TA, your pH should rise more slowly. Keep in mind that maintaining the TA that is required by your warranty is more important than doing this.
2- Consider disabling or turning off the ozonator. Also consider aiming jets so they don't break the surface as much and lessening use of waterfalls, pool slide water, etc. Eliminate sources of aeration that are avoidable.

Review ABCs of Pool Water Chemistry and other articles that more thoroughly explain the function of pH, TA and CSI.

 

[gold1]

Thanks, I have tried the ozone on and off and it does not seem to affect the pH. I actually forgot to turn it on almost 2 weeks ago and the rise was still there. I do not run the water fall unless the pool is being used, which is not much. Returns are hardly breaking the surface, just enough to move leaves etc. into the skimmers. I will try and lower the TA again, but worry about it being below what the manufacturer recommends for warranty purposes.

 

[JVTrain]

If it's simply because it's below a manufacturer recommendation, ignore it. The composition of your chemistry and the resulting CSI number is what matters.

However, if that recommendation is tied to a warranty. Keep it in that range. Having an active, valid warranty is much more valuable than a few more jugs of acid. And as HouTex said, new plaster pools will have higher pH rise for the first year or so as the plaster fully cures.

 

[gold1]

I asked what would void the warranty and was basically told that problems stemming from lack of proper care and water balance, the builder also has a 3 yr warranty on everything on top of the finish warranty. I wouldn't see how TA a bit lower than the 80-110 they recommend would be that big a deal.

 

[pwrstrk]

IMO, I would maintain the water chemistry per what the warranty states. My thinking on this, is to error on the side of caution. If there was a problem and they came out and tested the water and found levels out of range for what they recommend they could void the warranty if they choose to.
If it were me having to deal with adding acid however often to keep PH in check and having no warranty issues is what I would be doing.
It's all part of pool ownership in the beginning. You just shelled out X amount of money why create a problem that may cost you more.
Just my 0.02 for what it's worth. ?

 

[gold1]

Well I have enough MA in the garage to last quite a while…..the lady at the hardware store probably thinks I have a meth lab or something!! I guess my main concern was maybe hurting something in the long run with so may acid additions. Its not really a hassle as I add it when I do the cl after testing. Ill just keep on doing it, thanks for the advice!