Borax and Dry Acid instead of Borax and Muriatic Acid?

DaciaT

Member
Jun 17, 2019
14
Breaux Bridge, LA
I want to add Borax to my pool. In studying a few threads, including the detailed "How and Why" article, I haven't found mention of using dry acid in conjunction with the borax; only muriatic acid. Is this not an option? I'm asking because I have "Ph Down" on hand, so if it would work just as well, I'd like to use it.

If yes, my next question I suppose is some guidance on how much to use. Couldn't I just wait a day or two for the borax to take hold, and then use the Pool Calculator app to tell me how much Ph Down product to bring it back down?

Final question. I don't have a borate test. Could I assume my borates are zero, and use the Pool Calculator's recommended amount of borax, and then just assume the level of borates will be correct?

I filled pool from the water hose 5 days ago. Using the HTH 6-Way. My pH is 7.5, TA 320, OTO 5+ (looks to be a 6, one level brighter yellow than 5), CYA 40.
 

justinc

Gold Supporter
Apr 3, 2019
591
Texas
I would not add borates to a freshly filled pool until you have a better handle on the chemistry. Especially with a total alkalinity of 320. Wait until you numbers are all within range and stable before adding.

Muriatic acid is recommended over dry acid because it will not add sulfates (sulfur) to the pool. You can use it if you want but keep this in mind, especially if you have a salt water generator (dry acid is not recommended for those with SWCG).

In order to take a 2,640 gallon pool from 0 ppm borates to 50 ppm borates you need to add 155 oz by weight of borax. Then, add 74 fl oz by volume of Muriatic Acid 31.45% to compensate for the pH increase.

If you wanted to use dry acid instead, you would need 106 ounces by weight to give you the same pH lowering effect as 74 ounces of Muriatic Acid.

You won't need a way to test in the beginning because you can safely assume you are at 50 ppm but may want to order some borate test strips to check your levels in a few months because it will drop a few ppm per month from splash out/backwashing.
 

DaciaT

Member
Jun 17, 2019
14
Breaux Bridge, LA
I would not add borates to a freshly filled pool until you have a better handle on the chemistry. Especially with a total alkalinity of 320. Wait until you numbers are all within range and stable before adding.

Muriatic acid is recommended over dry acid because it will not add sulfates (sulfur) to the pool. You can use it if you want but keep this in mind, especially if you have a salt water generator (dry acid is not recommended for those with SWCG).

In order to take a 2,640 gallon pool from 0 ppm borates to 50 ppm borates you need to add 155 oz by weight of borax. Then, add 74 fl oz by volume of Muriatic Acid 31.45% to compensate for the pH increase.

If you wanted to use dry acid instead, you would need 106 ounces by weight to give you the same pH lowering effect as 74 ounces of Muriatic Acid.

You won't need a way to test in the beginning because you can safely assume you are at 50 ppm but may want to order some borate test strips to check your levels in a few months because it will drop a few ppm per month from splash out/backwashing.
Thanks for answering my questions! I will wait until my water is stable. Right now, I'm still struggling with trusting the OTO chlorine test. It's been quite high, and I hate to assume it's FC and not too much CC. While my chlorine is high, it's my understanding I shouldn't really attempt adjusting PH. And until I can adjust PH...I really can't be concerned with adding borates. But I plan to eventually...have my borax boxes on standby...and wondered about the muriatic vs dry acid. Thanks again!
 

justinc

Gold Supporter
Apr 3, 2019
591
Texas
Even though your pool is smaller, if you are going to be adding borates you probably don't want anything to go wrong that would necessitate a water exchange. It may be prudent to go ahead and purchase one of the more advanced test kits such as the TF-100 or K2006C.
 
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justinc

Gold Supporter
Apr 3, 2019
591
Texas
Agree with James. You can just add 6 and a 1/4 pounds (6.25) lbs of boric acid and be done with it.

Many folks around here buy boric acid from Duda Diesel. Here's a link to a 10 lb bag: Granular Boric Acid, 10 lb - FREE SHIPPING [boric10f] | DudaDiesel Biodiesel Supplies -- $25 and free shipping.

The only side effect will be a drop in your pH by about 0.3... so you would then need to add 7 ounces of 20 Mule Team borax to bring it back up to where you started.

Keep in mind Borax and Boric Acid are not exactly the same thing. Both add borates to the pool but have different effects on pH.
 
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