Lowering PH - Lowering TA

[Renloos]

I just bought a bottle of Muriatic Acid from Home Depot. I looked for the % and found that it says 20%. Pool Math has Muriatic Acid at 14.5% and 29%. Is there a formula to use when I have a different percentage than the Pool Math app? My PH is creeping up because my TA is high (160), so I'm working on getting that straightened out. PH is only 7.8 right now, but has been creeping up consistently over the last few days. (we've only had the pool open for a little over a week.)

And just so I understand correctly, to lower TA, I should aim to lower PH to 7.0-7.2 with muriatic acid then aerate to raise the PH up again? I would aerate with the jet turned up, SWG and kids playing. Does that sound right?

24' above ground, SWG, DE FIlter, TF-100 with Speedstir

 

[Texas Splash]

You have the lowering TA process correct. As for the % though .... just to be sure ....... any chance what you saw listed as "20" was the Baume and not the actual percentage (31.45%)?

 

[Renloos]

I couldn't find any % on the bottle, so I looked on the company's product page. Under FAQ for the product, it said, "This product contains 20% Hydrochloric acid."

 

[Texas Splash]

I don't use HD's HDX acid, but @mknauss does. Marty, how do your bottles look?

 

[mknauss]

HDX has two products in the Garden/pool section right next to each other. One is 31.45%, the other is 14.5%. At least my nearest Home Depot (Bullhead City, AZ). They come in a box with 2 one gallons containers in it.

 

[Renloos]

My local Home Depot and Lowe's do not have a pool section. Probably because it's Ohio. This is what we bought near the paint section. The guy that helped us find it said it's what he used in his pool. The website for the company said it was 20% muriatic acid. Do you think it's ok to use?

 

[mknauss]

Green -- they do not advertise a specific %. I believe it is close to 14.5%.

The pool section in our Home Depot is in the Garden section - outside.

 

[mknauss]

Not sure where you are in Ohio - I picked Akron - the Home Depot in Cuyahoga Falls shows having the 31.45% two packs. 86 in stock.

 

[Renloos]

Ha! You are close! Cuyahoga Falls is about 45 mins away. We have a few closer to us so that's where we looked. Yes, we checked outside too...then asked and were told they don't have a pool section at our Home Depot. I guess that's what we get for only having 4 good swimming months out of the year!

So, in your opinion, should I not use what I purchased?

Thanks so much for your help!

 

[Donldson]

If you have a Menards anywhere near by they have well priced full strength muriatic acid in the paint section.

 

[mknauss]

So, in your opinion, should I not use what I purchased?

You can use it. Assume it is 14.5%. Check pH after adding it to see if it matches your target.

 

[IceShadow]

I had some 20 Baume left over from the former homeowner but bought the same MA that the original poster did. Good info to have!

 

[Renloos]

Update and Question: I'm slowly getting my TA lowered so thanks for the help!

My question is: Would you rely most on a $15 PH meter (came free with my TF-100 kit), or the color matching test block from the K1000 set (using the 5 drops of red regent)? I calibrated the PH meter with two different test packets. I'm getting a higher reading every time with the PH meter. It might say 7.8 when my color matching to the test block will say 7.5. I'm not sure which one to believe!

 

[mknauss]

Test block.

I would not make chemical addition decisions based on the meter. It is OK to say 'in range'.

 

[Renloos]

Test block.

I would not make chemical addition decisions based on the meter. It is OK to say 'in range'.

OK! Thank you!!