Lowering Total Alkalinity and Raising CYA

[rpk1430]

Hi all,

I've been dealing with high Total Alkalinity and have attempted to lower by adding acid (muriatic) down to 7.0 and then aerating. This was only able to lower the TA from about 150 to 110. TA then went up to 120, and after coming back from a 3 week vacation t has gone back up to 150. Do I just repeat the same procedure again, or is there something I'm missing here? I had been getting a lot of crystal flakes from the inlet to the pool, which has reduced significantly after this first attempt but the TA is still high. My recent test were FC 7.0/CC 0.5/pH 7.6/TA 150/CH 450/CYA 40/Temp 81/Salt 3050. CSI is at 0.3, I don't really see much signs of scaling, just the flat crystal flakes. I also have the SWG to shut down about 15 min before the pump to try and prevent flakes and I recently acid washed the SFG.

The other issue is the CYA is still low at 40. When I checked it before I left on vacation it was also around 40, and then I added about 5 lbs of dry CYA (into skimmer inside a fine mesh bag) and was expecting it to be much higher when I returned but still stuck at 40. The pool has an auto cover. I'm going to add more CYA again, but this seems really unusual so wanted to ask the experts on the forum.

Thanks!

 

[PoolStored]

Do I just repeat the same procedure again

Yep.

Flakes from the SWCG. because of the TA and CH. Easier to fight TA than lower CH. You can also run your pH lower to help CSI.

If your water temp is 90 or above, CYA degrades faster.

Here are some tricks on the Aeration front:

Lowering Total Alkalinity (TA) Quickly with the Acid Aeration Method

Thought I'd make a post that might help others. We've had quite a few members this year with high TA, and I've been typing the same information over and over. I'm going to post this so I can link it to help others. High TA can cause rapid pH rise. High TA is typically caused by high TA fill...

www.troublefreepool.com

 

[rpk1430]

Yep.

Flakes from the SWCG. because of the TA and CH. Easier to fight TA than lower CH. You can also run your pH lower to help CSI.

If your water temp is 90 or above, CYA degrades faster.

Here are some tricks on the Aeration front:

Lowering Total Alkalinity (TA) Quickly with the Acid Aeration Method

Thought I'd make a post that might help others. We've had quite a few members this year with high TA, and I've been typing the same information over and over. I'm going to post this so I can link it to help others. High TA can cause rapid pH rise. High TA is typically caused by high TA fill...

www.troublefreepool.com

Thanks Pool Stored! I did read. your post on lowering TA and found it very helpful, and will probably invest getting an aerator like yours setup in the future. In the interim, I was wondering if you (or any other experts) had thoughts about not lowering the pH all the way to 7.0 (maybe 7.2), and doing the aeration slower in increments. I ask because of various factors including PG&E's time of use electric costs and wanting to preserve heat in pool with pool cover at night and also wanting to use the pool during aeration (I won't be using a sump pump). I'm also curious about it from a pure scientific/chemistry standpoint. Essentially, is there any significance to the rapidity and/or duration of aeration in bringing the pH level up in terms of its ultimate effects on target TA? Or is it more a convenience factor of getting it accomplished in the quickest period of time?

 

[PoolStored]

Yep, slower is just fine. Convenience factor.

 

[rpk1430]

Thanks, you are awesome!