Frequency of adding acid to a pool with a water feature

[AaronGo]

This is inspired by the following post from another thread:

Do you have a water feature, spa spillover, or SWG? All of then aerate the pool and thus raise the pH. Also if your TA is high, this too pools the pH up.

Our pool has a spillover but no other water features. Should I expect to have to add acid on a fairly regular basis as a result due to the extra aeration? Our pH being high makes more sense since it's been raining a lot this past week + the spillover supplying extra aeration.

Just curious what others with water features encounter wrt the frequency of adding acid. If you took two pools with the only difference being some type of water feature (say a spillover), is there a reasonable estimate of how much extra acid needs to be added?

Thanks for the help, I'm trying to learn about my pool as quickly as I can!

 

[jblizzle]

Hard to say how much more acid. Just that it is likely to be more.

If you work to keep your TA lower, then the pH may stabilize or at least not rise as fast.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone

 

[flipflop]

We don't have a permanent water feature, but I do have a "fountain" thingy I fashioned from PVC to stick into a return jet to try and get some overnight evaporative cooling when the water temp gets too high. I've definitely noticed that pH creeps up when I've been running that a lot. I think the general rule of thumb is that if you do ANY kind of aeration you should plan on paying closer attention to your pH than would otherwise be needed.

 

[Speedo]

I add acid every 2 days when running my fountain, bringing it down to 7.2 it usually jumps back up to 7.4-7.5 after roughly two days worth of use. Around 24-30hrs of actual use over 2 days.

Just guessing, but maybe a spillover wouldn't aerate as much as a fountain and therefore not as much of a pH increase.

W/o the fountain my pool has been indefinitely stable at 7.5.

 

[phipsi1237]

I have an attached spa with a spillover, which just about runs anytime the pump is on. 14,400 gallon pool. TA stays at 80. I add about 11-13 oz of 31.45% MA every 2 days to maintain 7.5-7.8ph. (approx 1.5 gallons per month)

 

[AaronGo]

thanks for the info. It's good to hear what others are doing so I have a better idea of what to expect.

I have an attached spa with a spillover, which just about runs anytime the pump is on. 14,400 gallon pool. TA stays at 80. I add about 11-13 oz of 31.45% MA every 2 days to maintain 7.5-7.8ph. (approx 1.5 gallons per month)

this is closer to my setup. While all pools are different, I have a feeling I will be adding a little acid every 2-3 days.

 

[JasonLion]

By lowering your TA you can reduce the frequency of acid additions, or even eliminate them completely. Try lowering TA down to 60.

 

[AaronGo]

The TA test from 7/12 came in at 60, fyi. I will re-test pH tmro, but it was still too high after today's test, probably closer to 8 than it was on 7/12 (was over 8 on 7/12).

Is TA something that should remain fairly consistent like the CYA level? Curious how often most TFP members have to adjust their TA.

 

[flipflop]

Pool School is your friend:

• Add acid to lower your PH to between 7.0 and 7.2 (this also lowers TA)
  Aerate until PH rises to around 7.6 (the only way to raise PH without also raising TA)
  Repeat steps 1 and 2 until you reach the desired TA.

 

[JasonLion]

If your TA is already down at 60, and you are still experiencing PH rise, you might want to try adding borates to the water. With borates at 30 to 50, you can lower TA further, down to around 40, which will further reduce, and hopefully stop the PH increase.

TA normally remains fairly steady. However there can be several exceptions to that. If you are constantly adding acid to maintain PH, the TA will tend to go down. If you have high TA fill water, the TA will tend to go up any time you add water to the pool. The TA will also tend to go down if you are using trichlor or dichlor, both of which are acidic, and are not maintaing the PH with soda ash.

 

[AaronGo]

Pool School is your friend:

• Add acid to lower your PH to between 7.0 and 7.2 (this also lowers TA)
  Aerate until PH rises to around 7.6 (the only way to raise PH without also raising TA)
  Repeat steps 1 and 2 until you reach the desired TA.

Thanks, I have read the Pool School extensively My TA is around 60 now, so the above would work well if my TA was 90+, for instance. But I don't want to lower my TA any more than it currently is, unless I am missing something.

If your TA is already down at 60, and you are still experiencing PH rise, you might want to try adding borates to the water. With borates at 30 to 50, you can lower TA further, down to around 40, which will further reduce, and hopefully stop the PH increase.

Thanks, I will make a note of this. I am going to do more testing this week as I work to get the levels in balance. After I get a feel for the daily pH levels I will see about adding some borates, but I need to better understand how and why to add borates to a pool.

 

[flipflop]

Totally missed that your TA was already at the low end of normal. That does make it a bit trickier!

We're pretty lucky in that our TA stays pretty steady at around 100. But at some point I'll be adding borates to the pool and will probably want to bring that down.

 

[AaronGo]

No worries TA of 60 is borderline low, so I will give it a little more time before deciding how to address the TA. I first need to see if I can get my pH relatively stable or if I am one of those who has to add acid every 2-3 days. Then I will know which avenue to take to address the TA.

 

[danivdp]

I have a spa spillover, and rarely (maybe every 3 months?) add acid. TA is at 100 (although it will drop to 60 before I add baking soda once a year) PH stays between 7.4 and 7.6 without regular chemical manipulation. Sometimes the PH will jump to 7.8 and I'll bring it down to 7.4.....like every 2 or 3 months.