Consistantly high pH

[JimB]

Since I opened the pool on May 27th it's been a constant battle to get my pH to stay in range. I go by the poolcalculator goals. So far this year I've added 13 cups of muratic acid. The pool has remained nice and clear all year and I've averaged 1 1/2 qts of bleach daily. (low reading today was because I missed testing yesterday and it's been bright and sunny.)

Today's readings--FC 1 (added 3qts 6%0) pH 8.2 maybe higher because the color was ruby red (added 2 cups muratic acid) T/A 80

Last year I had no problems with pH. It was consistent in the 7.3-7.5 range and T/A consistent at 90.

This first half of this summer has been very rainy and I thought that might have had something to do with the high pH. But I think I read somewhere on this sight that rain shouldn't affect pH. And we haven't had rain for a week now anyways and it's still high.

Thoughts/Suggestiions?

Thanks.

 

[woodyp]

Rain is MOSTLY PH neutral....but it's action breaking the water surface when raining cause the pool to outgas. I got 2.75 inches of rain this morning and just dumped 24 oz. of MA in mine as an example. The harder the rain..the more it rises. Maybe your pool likes a higher TA range?

 

[HamburgerChef]

Just curious, How old is your PH reagent? Only time I saw ruby red was when mine had gone bad. Is the reagent bottle stained red?

 

[jblizzle]

Good point by the Chef ... and where do you store the kit.

 

[chem geek]

Also see Recognizing a Compromised Reagent.

 

[JimB]

Woodyp, that does make sense. The rains we had were frog stranglers. With the exception of the last 7-8 days with no rain.

The pH regent is almost brand new. Bought it late last year direct from Taylor. And no the bottle is not stained red. During the winter the test kit is stored in the basement with a constant running dehumidifier. Dry as a bone down there. During the summer in a cupboard upstairs which is a/c controlled. I looked at the link 'Recognizing a Compromised Reagent' as it said if Phenol Red the solution changes from red to a yellow or purple.

Just tested pH and it reads between 7.5 and 7.8. (The color match is between.) It's been about 3 hours since I added the MA. I'll test again tomorrow but we're supposed to get some storms overnight into tomorrow.

Another ? woodyp. You suggested maybe my pool like a higher TA. I do like to keep it at 90 (which it held beautifully last year) but it's been holding at 80. I did add 1 lb soda three times this year (May 30, June 7 and June 30.) I thought I read somewhere here that raising TA will also cause the pH to go up.

Last ?. I have been thinking about raising the TA to 100. The reason....My brother's pool liner is very wrinkled. Someone told him that that was because his TA is to low. I don't know what his numbers are. He also uses baquacil and I've been trying to talk him into going BBB.

Thanks again.

 

[jblizzle]

The higher the TA, that faster the pH will rise ... I would have left is at 80 myself.

The TA itself had nothing to do with a wrinkled liner.

 

[JamesW]

The rule that I use is that if the pH is constantly too high, then the TA is too high. And, if the pH is constantly too low, then the TA is too low. I adjust the TA based on the pH. Once the TA is right, for that pool, then the pH stays right (Assuming no change in chlorine sources).

Based on your pH being constantly too high, I would lower the TA until the pH stabilized.

Why you did OK with a TA of 90 last year can be due to several possible reasons:

1) Less aeration.
2) Lower temperature.
3) Some source of acid (such as trichlor).
4) Higher CYA level. (CYA makes up part of the TA, but does not contribute to pH rise).

At any rate, your current TA is not working, and I would suggest lowering it, or at least not raising it. Also, if your CYA is lower than 50 ppm, then you might want to consider raising it to about 50 ppm.

Regarding wrinkled liners: Very low pH causes liners to wrinkle, and pools that have very low TA (below about 30 ppm) will usually have very low pH. Low TA, by itself, won't wrinkle a liner, but there could be an indirect correlation without causation.

Note: If the TA is zero, or lower, then the pH is 4.5, or lower.

 

[Zadd]

Play with the TA a bit. I find that with TA at 80 I rarely add acid but with TA at 90 I have to add quite a bit if acid.

 

[JimB]

Today's test FC 1.5 (was busy yesterday and forgot to check it); CC 0; pH 8; TA 70; CYA 40; temp 85. The water is crystal clear. Two nights ago we did got about 1 1/2 inches rain. I don't have a rain gauge but a guess from my pool level Friday evening to Saturday morning.

JamesW & Zadd, I understand what you are saying regarding pH vs TA. But it has not held true for my pool in the past. Last year TA was consistent at 90 and pH hovered around 7.5. Occasionally down to 7.2 and the highest last year was 7.8.

JamesW, ref the reasons you suggested. #2 not it. We had about 35 days of 90+degee days. Unusual for this area. #3 Since joining this site I do not use any source with trichlor. #4 CYA held at 50 last year. #1 a possibility. Despite the high temps, pool didn't get a lot of use so no splashing around. Drought conditions so not much rain compared to this year.

I did have my CYA up to 50 earlier this summer. I'm thinking the amount of rain we have had this year may have diluted it some.

The TA causing a wrinkled liner was said by my brother. I think his pool store told him that. Since joining this group, I don't listen to the 'experts' at the pool stores.

For now I'm going to get the FC back up to 4; add 2 cups acid; leave the TA where it's at. Test again tomorrow. If CYA is still 40, raise it to 50.

As I wrote above, the water has remained very clear. This is the first year I haven't had trouble with greening so no shocking needed (knock on wood.) Chemistry was my worst subject in school. I hope the above didn't sound argumentative. I'm just trying to figure out why.

Thanks again for everyone's help.