PH way too high

[BrattyBrea]

Hello, I inherited a pool that had great readings all summer but I didn't know what I was doing, blissful ignorance.

After covering with a solar cover, I now have an algae bloom that won't go away even after shocking. I have done my research and I need to get my PH down to start a SLAM.

My PH has read 8.4 for a bit now which is the highest level the test will go.

I have added 5lbs of dry acid and 1 gallon of 31% MA with no change to PH.

Pool calculator is recommending 7lbs of dry acid but the sheer amount I'm putting in makes me nervous.

21k gallon above ground vinyl pool with cartridge filter, normally chlorinate with trichlor tabs in a feeder (but not currently as it's just disappearing)

 

[PoolStored]

Welcome to TFP!!!

First, how are you testing? What test kit do you have?

Second, stop using dry acid.

Third, use pool math to calculate how much muriatic acid to add to reduce pH by .4. Link-->PoolMath

Reduce pH in .4 increments, you can re-test after 30 minutes, and re-add enough acid to reduce another .4, until you reach 7.2 to 7.5. This is a reliable and safe method.

 

[BrattyBrea]

I have 3 test kits: HDX, Taylor 1000, and HTH test strips, all say 8.4.

I am using pool math.

Per their calculations my pH should have went down 2.1 after my chem additions!

No movement in Ph with either version of acid, that I mixed and poured in every 30 minutes over the course of 24 hours, testing every time.

 

[Donldson]

Welcome to TFP!

To get this out of the way: if you intend to perform the SLAM Process you are going to need a proper FAS-DPD kit such as the TF-100 or Taylor k2006c. None of the tests you have are sufficient to do this (and the strips aren't sufficient to do anything worthwhile).

Ok, so it sounds like your pH is quite high and will take some effort to lower. Pool calculators such as PoolMath are not good at calculating large pH changes. It can easily end up being way too little, or way too much. The best option is to use the highest level of the k1000 (the best tester of the three you list) and calculate what to add to reduce that to 7.2. Add that, retest after an hour of circulation, and repeat until you get a reading. It's the safest and most reliable way to lower extremely high pH levels.

 

[mknauss]

Welcome to the forum.
Have you done the TC - OTO test (yellow one) on the K1000? Be sure to do that. It should tell you if your TC is very high and could be interfering with the pH results.

 

[BrattyBrea]

Thank you all for your responses, I will persist with the MA in small amounts, I just didn't want to believe my pH was so high.

 

[BrattyBrea]

Welcome to the forum.
Have you done the TC - OTO test (yellow one) on the K1000? Be sure to do that. It should tell you if your TC is very high and could be interfering with the pH results.

I did, yes. It's at 0 (on purpose)

 

[mknauss]

FC should never be at 0.
Since you did not have a reliable way to actually measure the FC, just wanted to check.

 

[BrattyBrea]

I have upgraded to the Taylor 2005c and persisted with the MA in small amounts and it worked!
By calculation, my Ph was almost 11! Wow.

Thank you all again!

 

[dfwnoob]

Pick up the Taylor K-1515A FAS/DPD test and that will turn your current kit into the recommended K-2006C. It'll be useful to have in the future.

 

[BrattyBrea]

Pick up the Taylor K-1515A FAS/DPD test and that will turn your current kit into the recommended K-2006C. It'll be useful to have in the future.

I did this exactly and saved some money, thanks!