Normal to need this much acid

[smcdonald001]

Hello all,
So we have had our new pool up and running for almost a month. We really have everything almost dialed in perfectly.

FC 5
CYA 70
TA 70
CH 310

But one thing I am noticing is our pH is constantly rising. Will go from 7.6 to 8.2 in about 2 days. We are using between 1 and 2 gallons of 31.45% muriatic acid a week. Is that normal? Is it because the pool is new? Pool is about 16k or 17k gallons.

I have recentally added borates to see if that can help control the pH drift, but doesnt seem to help so far. But the borates definately make the water shimmer.

 

[mknauss]

The curing of the plaster will take many months to a year. Your pH rise will slow down over time due to the plaster curing.

Use of water features causes aeration that also raises pH. You have quite a list of those in your signature. If you use those regularly, they will push your pH up.

 

[smcdonald001]

We only use the features for maybe 1 or 2hrs every day or two (when we swim). So any idea what a "normal" amount of pH rise will be once the pool has finished curing.

 

[mknauss]

Depends on water chemistry, fill water use and chemistry, etc. Some never have to adjust the pH. Others, like me, have to adjust it weekly or more often, especially in summer. I have high TA fill water and huge evaporation. So pH is constantly being pushed higher.

 

[Jimrahbe]

001,

I use about 20 oz of acid per week...

The lower you try to keep the pH the more acid it will take.. I suggest that you let the pH get to 8.0 and then only drop it back to about 7.7..

Thanks,

Jim R.

 

[smcdonald001]

Ok I was thinking of going the intellichem or intelliph route, but reading all the bad reviews on here has me rethinking that idea. I think we will just stick it out to the end of 2021 and see how much acid we will be using at that time

 

[smcdonald001]

Jim, pool math app says 7.6 is my target. But I always add enough to take it down to 7.4 because I was thinking that if I only lowered to 7.6 or 7.7 that it would be back up to 8 or 8.2 in less time. Is my thinkong wrong?

 

[CrystalRiver]

It will get from 7.6 to 8.0 faster than from 7.4 to 8.0, but it will take more total acid over time to do it that way.

 

[Dirk]

I've found it's exponential. Going from 8.0 to 7.8 (2 points) takes way less acid than going from 7.6 to 7.4 (even though it still 2 points). Let your acid ride closer to 8 and you'll use less, a lot less.

Three years later and my pool still needs acid, every week. There is no "norm," there are a lot of variables, including fill water chemistry. Some say the SWG contributes to pH rise as well. Certainly your water features do too. Also, kids are water features! Splashing in from the slide, jumping in, water fights, etc all contribute to pH rise.

I have an IntellipH and swear by it. No problems. Not sure what bad reviews you're hearing, mine works great and has uninterrupted since I installed it a couple years ago. Now IntelliChem is a different story. I've never had one, but know a little about how they work. It's an expensive system, but I wouldn't want one if someone gave it to me and installed it. My IC40 and IntellipH are the perfect combo for me, and my pool maintenance during swim season is very little. I barely touch chemicals for months at a time.

 

[setsailsoon]

I'm guessing my water is very similar to yours. I had the same problem first few years. I was adding acid 3 times per week first year or two. I reduced TA to 50 and raised the target pH to 7.8. This helped a lot but still needed acid more frequently. So I switched to borate buffer pool. Very easy to do and helped even more. Acid additions reduced to weekly or less. It seems like curing also takes longer than a year around here since I didn't change anything else but over time my acid consumption has dropped way lower. During this year (year 7) my acid addition dropped to ~2 times per month. Seems to stay at 7.8 for long periods then creep up. After it's 7.9 for a few days I add acid. I just watch the CSI calculation to be sure I don't go positive. I switched to salt a couple years ago and it doesn't seem to have had any affect. TA and borate plus a long time for the plaster to cure seem to be needed around here to stabilize pH.

Chris

 

[Belikin]

I was having this same question! My pool has been active only since August and I too am using what feels like inordinate amounts of acid, just about the same amount you are. Thanks for your responses guys, it helps me as well. I'm now looking at getting and installing the intelliph because I like automation alot and dislike seeing ph of >8.5 EVERY single time i test. (That's what it feels like anyway)

 

[Jimrahbe]

Jim, pool math app says 7.6 is my target. But I always add enough to take it down to 7.4 because I was thinking that if I only lowered to 7.6 or 7.7 that it would be back up to 8 or 8.2 in less time. Is my thinkong wrong?

001,

I look at it like a rubber band.. The further you pull it from where it wants to be the harder it tries to bounce back..

If I lower my pH to say 7.2, it only takes about a microsecond to bounce back to 7.4.. But my pool will stay at 7.7 or 7.8 for several days before slowly moving up to 7.9 or 8.0.

I like your idea of a waiting for while before deciding on an automated system of some kind.. I would not suggest the IntelliChem.

Thanks,

Jim R.

 

[setsailsoon]

Jim,

Rubber band explanation is a great one!

Bel and SMC, I get the frustration on this and I was thinking about the same solutions with some kind of acid feed system. Glad I didn't do it. Just more things to take care of and after a couple of years acid requirement dropped a LOT! In the long run unless you have a water park of features the acid addition frequency will not really justify the equipment maintenance.

Chris