Lowering PH

[cacciato2006]

I left the pumps running last night to aerate with the PH at 7.1 and TA of 150. This morning the PH was 7.8 and the TA was 170. The pool appears full and and I don't think any additional top of water went in so I'm not sure how the TA went up unless it was user error on the the testing.

Looking at pool math "effects of adding" it says if I add 1 gallon of 31.45% MA it will lower the TA by 17. If I'm at 170 and need to be at 60 I guess I need another 6 or so gallons of MA. Does that sound about right? Could I just add a gallon every hour or so?

 

[PoolStored]

I left the pumps running last night to aerate with the PH at 7.1 and TA of 150. This morning the PH was 7.8 and the TA was 170. The pool appears full and and I don't think any additional top of water went in so I'm not sure how the TA went up unless it was user error on the the testing.

Within testing error. Do you have a speedstir? Might want to get one.

Looking at pool math "effects of adding" it says if I add 1 gallon of 31.45% MA it will lower the TA by 17. If I'm at 170 and need to be at 60 I guess I need another 6 or so gallons of MA. Does that sound about right?

Sounds about right.

Could I just add a gallon every hour or so?

Remember...POP. NO. You can crash your pH. If you feel the need to do it every hour, test pH and just add enough every hour to get your pH back to 7.0. No more.

 

[cacciato2006]

Your CYA is 50. We only measure at the lines, not in-between. It is a log scale, so only lines. GET THAT FC UP NOW. Minimum and below is LAVA. Get some liquid chlorine in today. FC IS A DAILY test and replenish. You may be ok, because the water is cold, but always FC first.

OK on CYA reading. I last time i put in MA about 30 minutes so I'll run over and dose 10% liquid chlorine from 3% to 6%. Water currently looks great but it is 58 degrees.

 

[PoolStored]

I last time i put in MA about 30 minutes so I'll run over and dose 10% liquid chlorine from 3% to 6%. Water currently looks great but it is 58 degrees.

You are maybe ok. Algae growth is minimal in cold water, but minimum is lava. If you are using pool math subscription, go to the gear in the upper right and click. Scroll to bottom and enable sharing logs with TFP, then we can see how your FC is holding and your tests and additions.

 

[cacciato2006]

Within testing error. Do you have a speedstir? Might want to get one.

Sounds about right.

Remember...POP. NO. You can crash your pH. If you feel the need to do it every hour, test pH and just add enough every hour to get your pH back to 7.0. No more.

I have a speedstir. I'll go get the additional MA. I spent most of yesterday pool side adding MA a little at a time. The lowest I could get the PH before I left for the night was 7.1 while adding three gallons during the day and this morning it was already back at 7.8. I tested the ph no less than 10 times.

 

[cacciato2006]

You are maybe ok. Algae growth is minimal in cold water, but minimum is lava. If you are using pool math subscription, go to the gear in the upper right and click. Scroll to bottom and enable sharing logs with TFP, then we can see how your FC is holding and your tests and additions.

I enabled sharing of logs with tfp. I've checked the link from user profile and the unique link.

 

[cacciato2006]

PoolMath Logs

 

[Bperry]

You are worrying a lot about TA, but it’s the least important of all those. Just manage the pH to stay in the 7’s and the TA will fix itself with no additional effort from you over time. The high TA will force you to add acid frequently but it’ll slow down as the TA comes down. IMO, you should be more worried about the pH with all the huge acid additions. Try checking the pH after adding acid to make sure it doesn’t get below 7.0

 

[cacciato2006]

You are worrying a lot about TA, but it’s the least important of all those. Just manage the pH to stay in the 7’s and the TA will fix itself with no additional effort from you over time. The high TA will force you to add acid frequently but it’ll slow down as the TA comes down. IMO, you should be more worried about the pH with all the huge acid additions. Try checking the pH after adding acid to make sure it doesn’t get below 7.0

My feed water has a TA of 340 so not sure how it will fix itself. Ph is in good range chlorine should be today.

 

[pjt]

not sure how it will fix itself.

Adding MA to reduce pH will also reduce your TA. Focus on managing your FC and pH. TA is the least important parameter of pool chemistry, and it will come down over time with your pH management MA additions. Try to minimize adding fill water.

 

[PoolStored]

My feed water has a TA of 340 so not sure how it will fix itself. Ph is in good range chlorine should be today.

Adding MA to reduce pH will also reduce your TA. Focus on managing your FC and pH. TA is the least important parameter of pool chemistry, and it will come down over time with your pH management MA additions. Try to minimize adding fill water.

@pjt and @Bperry, we are working on lowering TA significantly. @cacciato2006 is on the right path and knows what we are doing.

pjt and Bperry are spot on for normal maintenance. We teach people to manage pH and let TA be what it is. You are in a special case.

In this case @cacciato2006 you are executing a plan to aggressively lower your TA. You are good, keep going.

 

[Bperry]

@pjt and @Bperry, we are working on lowering TA significantly. @cacciato2006 is on the right path and knows what we are doing.

pjt and Bperry are spot on for normal maintenance. We teach people to manage pH and let TA be what it is. You are in a special case.

In this case @cacciato2006 you are executing a plan to aggressively lower your TA. You are good, keep going.

My point was that there’s not much need to lower the TA and the only thing it’s hurting is the pH stability right? Yes the fill water is high TA but a gallon or two a week of fill water in a 30,000 gallon pool is very minimal addition. The super fast pH rise and corresponding acid additions to bring it back down to 7.X will force that to come down on its own. I am more worried about the 2 gallons of acid that was added pushing the pH way below seven.

Just want to be sure the OP knows that the chlorine and pH are way more important than the TA and to be careful with the huge acid additions. Checking the pH after the addition would be a good safety plan.

 

[mgtfp]

I left the pumps running last night to aerate with the PH at 7.1 and TA of 150. This morning the PH was 7.8 and the TA was 170. The pool appears full and and I don't think any additional top of water went in so I'm not sure how the TA went up unless it was user error on the the testing.

Have a read through the Extended Test Kit Directions, in particular the Total Alkalinity chapter. In the notes you will find this:

Sometimes a static electric charge can build up on the R-0009 dropper bottle tip, causing the drops to be smaller than usual and making the test read higher than actual. You can prevent this by wipping the tip of the dropper bottle with a damp cloth or tissue before you start and after each drop.

Hold the dropper bottles vertically and squeeze gently, so that drops come out slowly and seem to hang on the tip of the dropper bottle for a moment before falling.

That might help to get more consistent test results.

 

[cacciato2006]

Have a read through the Extended Test Kit Directions, in particular the Total Alkalinity chapter. In the notes you will find this:

Sometimes a static electric charge can build up on the R-0009 dropper bottle tip, causing the drops to be smaller than usual and making the test read higher than actual. You can prevent this by wipping the tip of the dropper bottle with a damp cloth or tissue before you start and after each drop.

Hold the dropper bottles vertically and squeeze gently, so that drops come out slowly and seem to hang on the tip of the dropper bottle for a moment before falling.

That might help to get more consistent test results.

No, I hadn't read that and I was wondering why I was wiping the tip of that bottle each drop during that test. Thanks for clearing that up. I'll hold the bottle vertically and squeeze gently and see if I get a little different result.

I headed over to run the evening tests now. Thanks again.
David

 

[cacciato2006]

I may have figured out one of my problems. I just purchased this pool a few weeks ago. I contacted the pool company that serviced it and they told me it has 25k to 30k of capacity. The company that built it didn't have any records. I looked at the arial photo and measured the surface area and did not include the spa or the walk in entry and came up with 840sf of surface area. I'll measure the depth tomorrow but the deep end is at least 10 feet and maybe 12 feet deep. Roughly speaking the pool has to be at least 50k gallons and not the 30k I've been using. I've noticed several times I wouldn't hit the target the app suggested after putting in the recommend amount of chemical. This morning Fc was 3.0, the apps said add 115 oz of 10% liquid chlorine to get to 6.0 and I did. I rechecked at the end of the day and I was at 4.5 and not 6.0 or just 1.5 up. In the "effects of adding" in the app if I adjust the pool volume to get 1.5 up it says the volume is 60,000 gallons. This pool certainly is not 30k gallons if this is correct.
I'll take measurements tomorrow and see what I get.

 

[PoolStored]

I may have figured out one of my problems. I just purchased this pool a few weeks ago. I contacted the pool company that serviced it and they told me it has 25k to 30k of capacity. The company that built it didn't have any records. I looked at the arial photo and measured the surface area and did not include the spa or the walk in entry and came up with 840sf of surface area. I'll measure the depth tomorrow but the deep end is at least 10 feet and maybe 12 feet deep. Roughly speaking the pool has to be at least 50k gallons and not the 30k I've been using. I've noticed several times I wouldn't hit the target the app suggested after putting in the recommend amount of chemical. This morning Fc was 3.0, the apps said add 115 oz of 10% liquid chlorine to get to 6.0 and I did. I rechecked at the end of the day and I was at 4.5 and not 6.0 or just 1.5 up. In the "effects of adding" in the app if I adjust the pool volume to get 1.5 up it says the volume is 60,000 gallons. This pool certainly is not 30k gallons if this is correct.
I'll take measurements tomorrow and see what I get.

You will lose FC during the day. Entirely normal to lose 1.5FC during the day in tx in the winter.

Our procedure to adjust pool volume. When you make a change with pH or with FC (FC is best test), make your addition per pool math with existing volume. Retest 30 minutes after addition. If you don't hit your mark, raise pool math volume by 500. Wait for next addition. Continue this until you get to a volume where you get result you expect. Then stop testing after adding. If you are WAY off, you can start with 1000 gallon increments, no more.

 

[cacciato2006]

That is interesting. I'll start today. I need to bump up Fc 1.5 more.

 

[PoolStored]

That is interesting. I'll start today. I need to bump up Fc 1.5 more.

FC gets consumed by bathers, sun, organics in the water. Sun is the biggest user. Here in Ohio during June/July, with swimmers and sun, I can use up to 5.5 FC. Good luck on the sizing, always fun to figure out your actual pool volume using chemistry!

 

[jklocke]

I came across this thread this morning as I was looking at my winterized pool and wishing I could be outside working on it! I hope it's ok that I'm jumping in pretty far along.

This morning Fc was 3.0, the apps said add 115 oz of 10% liquid chlorine to get to 6.0 and I did. I rechecked at the end of the day and I was at 4.5 and not 6.0 or just 1.5 up. In the "effects of adding" in the app if I adjust the pool volume to get 1.5 up it says the volume is 60,000 gallons. This pool certainly is not 30k gallons if this is correct.

Like PoolStored said, if you're unsure of your pool volume, you need to check the results of your additions 30 minutes or so after you make them, not at the end of the day when you've lost some FC to UV and organics. It makes it much easier to know if your additions are enough or if something is off with the calculations.

There are several pool volume calculators online, like this one from Pentair - Pool Volume Calculator. I think that you're right that your volume is off some, but I don't think it's almost double what you had. Plug some measurements in, or google other calculators.

Good luck!

 

[cacciato2006]

Volume of the pool seems to be 50k instead of the 30k the pool store said it was. I am getting the adjustments to Fc/Ph as expected based on the 50k volume. I continue to add MA to keep the TA coming down. I started at 240 and last test was 120. I'll keep adding MA each day until I get down to 60. Thanks to all with the information I've been provided.