Adding Borates with Solubor

[scdaren]

Moved from Borates, heard of Solubor?

I wrote about this in the Borax Source thread. You can skip to the last post for the bottom line which is that you can use it as a source somewhat similar to 20 Mule Team Borax except that you use somewhat more by weight (10-20%) if you are using it to raise the pH while if you are using it to add borates, you add about half as much by weight and roughly half as much acid.

The following table shows the amount of borate product and full-strength Muriatic Acid (31.45% Hydrochloric Acid) needed to raise borates by 10 ppm in a 10,000 gallon pool and start and end with a pH of 7.5:

........................................................................................... Product Weight .................. Acid Volume
20 Mule Team Borax (sodium tetraborate decahydrate) ...... 117.75 oz. (1.64 boxes) ...... 56.4 fl. oz.
ProTeam Supreme (sodium tetraborate pentahydrate) ........ 90.0 oz. (5.6 pounds) ........... 56.4 fl. oz.
Boric Acid ........................................................................... 76.4 oz. (4.8 pounds) ........... none (pH drops slightly)
Solubor (disodium octaborate tetrahydrate; DOT) ................ 63.7 oz. (4.0 pounds) .......... 26.9 fl. oz.

Sorry to resurrect an ancient thread --- but I'm getting ready to add borates to my pool for the first time, and plan on using Solubor since we have tons of it at work and I can get it at no cost.

From researching on the forum, I found this old thread from chem geek showing the amounts to use (Solubor is not in Pool Math as far as I can tell).

Since this is 8 years old, just wanted to put it up to check and see if anything has been figured out since this time that would change the above numbers or caution against using Solubor instead of borax or boric acid.

And a side question -- I hate using the full-strength muriatic, can I just use a little more than twice as much of the 14.5%, or is it not linear?

Based on the above, I have a 15,000 gal pool, so I'm looking at adding 24 lbs. of Solubor to reach 40 ppm. Though I'll be doing it little by little and checking pH along the way, probably over the course of a couple weekends.

Also, my plan is to mix the solubor in water in a pail, then dump it in the pool -- please let me know if that's a bad idea for any reason.

Thanks!!

 

[scdaren]

Thanks mods... was not sure how to quote an old post into a new thread.

 

[pooldv]

I'm not familiar with Soluble and I'm not aware of any discussions in the last several years or any changes to what chemgeek originally said.
Yes, it is fine to use twice as much of the half strength MA.

 

[scdaren]

Just did my borates with Solubor, thought I'd post here in case anyone else is looking at Solubor.

On my 15k pool, which has never had borates before, I used 18 lbs. of Solubor and 2 gal. of 14.5% muriatic acid. I added the solubor by mixing 2 lbs. with pool water in a half full five gallon pail, and did 6 lbs. at a time. Here is the procedure I did:

- Staring pH 7.9, added 3 qts. 14.5% MA
- Added 6 lbs. Solubor, let mix for an hour
- pH was at 7.8. Added 2.5 qts. 14.5% MA
- Added 6 lbs. Solubor, let mix for an hour
- pH was again at 7.8, added 2.5 qts. 14.5% MA
- Added 6lbs. Solubor, let mix for an hour, then tested.

My final result was about 40 ppm borates (at least I think so, you can look at the pic of my test strip below and guess for yourself).

Water looks excellent, photo of that below as well.

Final test results:
FC 4.5
CC 0
pH 7.8
TA 80
CH 350
CYA 50
BOR 40
TEMP 50
CSI -0.16