Am I fighting a losing battle - 24 oz of MA a day to keep pH/CSI in check (CH high)

[QingGuy]

FC - 5
CC -.5
PH - 7.7
TA - 70
CH - 1000 - 1100
CYA - 80
CSI - .23
Salt - 4000
Water Temp 83

As subject says I seem to be on the losing end of fighting my pH and keeping my CSI in the negative. Is 24 oz a day of MA high? Based on my second year use (last year) after plaster cured for a year it seems high, I think last year I was going through about 8 oz a day.

I've bough my TA down as low as 50 and in a week it's back-up to the 70 range. Could this be caused by my high CH? Plan is to drain at the end of the season.

Based on the numbers above and pool math I just added 48 oz of MA (rounded-up from the 48 oz it suggested, I always have to round-up), that will drop me down to pH 7.2/CSI -.21, by Saturday (2 days) I'll be at 7.7/.23 again and have to add another 48 oz.

My pool gets very little use, a couple of days a week by 2/3 people.

Thanks for any tips!

 

[JoyfulNoise]

Borates?

Lowering your TA has nothing to do with CH. Your CH is high from evaporation and fill (I live in a desert too, my CH increases 250-300ppm per year just from evaporation).

What is the pH/TA/CH of your fill water?

 

[QingGuy]

@Joy - Sorry, typed this up while on a conference call, could have been a bit clearer. I mention TA because lowering my TA would slow the creep-up of my pH level which is causing me to use 24 oz of acid a day. Hope that makes sense.

You know I wrote down the pH/TA/CH of fill water, I'll look for that, BRB.

 

[Pyrodav]

Does it stay at 7.7? My pool seems happy to stay 7.6 7.7 for quite awhile. I also have 30-50 ppm of borates. Might wanna order some Boric Acid from Duda Diesel.

 

[QingGuy]

Borates?
What is the pH/TA/CH of your fill water?

Just tested:

pH - 7.7
TA - 140
CH - 240​

Does it stay at 7.7? My pool seems happy to stay 7.6 7.7 for quite awhile. I also have 30-50 ppm of borates. Might wanna order some Boric Acid from Duda Diesel.

It will rise to 8+. That's the highest I've seen it go, I usually catch it before it hits 8.

Yea, I've seen the borates suggestion before. May have to do some additional reading on the subject.

 

[JoyfulNoise]

Your fill water TA is problematic. As water evaporates and fill water is added, the makeup water is putting upward pressure on your pH from the TA. As you've said, you can lower your TA to 50ppm and it will pop back up to 70ppm in a few days. That's due to fill water.

I would suggest you read through the sticky on borates. If you do it right, it will lower the frequency of acid additions (but NOT the total amount of acid needed) which can make your situation a little less painful.

As others have stated, with borates in my pool water, the pH will hang at 7.7-7.8 for a long time.

Also, your CH rise is from evaporation. In the Las Vegas area, you can easily approach over 100" if evaporation per year. That means in one year, an uncovered pool will evaporate away most of its pool volume. Since your fill water is over 240ppm (I bet there are better and worse months for CH) you can expect that much increase every year.

 

[QingGuy]

Thanks for the info, just read-up on Borates and I think after I drain at the end of this season, when I re-fill I'm definitely going to add borates. If it's not going to drop the consumption of MA dramatically this season it doesn't make sense to spend $150 on borates only to turn around and drain the pool in 3 to 4 months.

My main concern isn't CH, pH, TA etc., it's CSI. I've been told with my high CH as long as I can keep my CH in the negative I'm good with my CH level, many people run their pools with that high of CH on here from what I'm told. Since pH seems to be the main contributor to high CSI (or at least high for me) controlling pH is the product of keeping my CSI low. I suppose for the rest of the season I'll just need to make sure we add that 24 oz a day.

@Joy - I'm curious, how much MA do you go through?

 

[JanHan]

I'm fighting the exact same battle with fill water that has 340 TA. I'm at the point of giving up and just saving the $$ I spend on acid and putting it in a fund for eventual new plaster.

 

[JoyfulNoise]

I'm fighting the exact same battle with fill water that has 340 TA. I'm at the point of giving up and just saving the $$ I spend on acid and putting it in a fund for eventual new plaster.

Wow, that's horrible fill water TA. When fill water TA is that high, the primary means of pH control is to reduce evaporation by keeping the pool covered. Covering the pool will reduce evaporation as well as keep CO2 from outgassing. Both of those will help to keep pH down.

When I cover my pool, my pH rise ceases to exist. I can make the pool sit at any pH I set it to.

 

[JanHan]

Wow, that's horrible fill water TA. When fill water TA is that high, the primary means of pH control is to reduce evaporation by keeping the pool covered. Covering the pool will reduce evaporation as well as keep CO2 from outgassing. Both of those will help to keep pH down.

When I cover my pool, my pH rise ceases to exist. I can make the pool sit at any pH I set it to.

I wish I could afford a cover at this point, I'm not even sure how I'd go about it with the shape of pool&attached raised hotub? And the fillwater situation is horrible. Its co-op well water that is overpriced and to really rub salt in the wound, we also received notice a few months back that the company had to disclose by law, that one of the levels in the water recently showed that it is cancer causing. But not to worry, they will be "adding a different filtration system by the end of the year." So I'm swimming in beautiful TFP water that is also cancer soup I guess? Sorry, I don't want to hijack this thread though.

 

[JoyfulNoise]

I wish I could afford a cover at this point, I'm not even sure how I'd go about it with the shape of pool&attached raised hotub? And the fillwater situation is horrible. Its co-op well water that is overpriced and to really rub salt in the wound, we also received notice a few months back that the company had to disclose by law, that one of the levels in the water recently showed that it is cancer causing. But not to worry, they will be "adding a different filtration system by the end of the year." So I'm swimming in beautiful TFP water that is also cancer soup I guess? Sorry, I don't want to hijack this thread though.

Feel free to start another thread in the Deep End sub-forum. Water suppliers are required by Federal EPA regulations to report certain chemical levels in drinking water and to send out warnings when those levels exceed threshold values set by EPA. Typically the threshold levels are set far below the "no observable effect level" (NOEL) out of an abundance of caution.

 

[JanHan]

Feel free to start another thread in the Deep End sub-forum. Water suppliers are required by Federal EPA regulations to report certain chemical levels in drinking water and to send out warnings when those levels exceed threshold values set by EPA. Typically the threshold levels are set far below the "no observable effect level" (NOEL) out of an abundance of caution.

Thanks, I might do that. Shuffling through papers trying to find the report.