Suggested Borate Levels

cjs

LifeTime Supporter
Jul 13, 2014
35
Cypress, TX
There is one pool store in my area that promotes Borates in your pool. They even have a program where they guaranty no algae if you follow their program. If you get algae, they will personally maintain your pool at their expense to get the problem resolved. Pretty good endorsement for Borates I'd say.

Here's the catch. They say the normal 35-55 ppm borates are not enough in this area (Houston, TX). I'm guessing long days of hot sun are the reasoning. For them to give the guaranty, you have to maintain between 70 and 90 ppm.

1) I have resisted using Borates because I have a dog and cat that do drink some pool water. I've convinced myself from my research that the 30-50 ppm is OK...but I'm certainly not convinced that at 70-90 it will still be OK.

2) I'm adding borates more for the look and feel, and less for the algaecide quality (because I've found algae isn't a problem if you keep the FC/CYA/pump times in check). With that said, is more borates better to prevent algae...or are they just selling more product by requiring you to be at higher levels?

Thanks in advance for any feedback.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
We don't recommend raising the borate level above 80, and have never run into a case where going over 50 was required or even helped noticably.

Are you sure your aren't mixing up borates with cyanuric acid? Most of what you just said makes a lot more sense if you/they are talking about the cyanuric acid level, which is very much related to the amount of sunlight your pool gets, while borates are not especially related to sunlight.
 

cjs

LifeTime Supporter
Jul 13, 2014
35
Cypress, TX
It's definitely borates. Your response suggests my suspicion that it's a way to sell more! They sell the pro team line of products.

I'll stick with the 30-50 recommended here. The pet issue was mandating that anyway.

One other thing...no one sells borate test strips...the only store that can even test for them are the one that promotes their use.
 

cjs

LifeTime Supporter
Jul 13, 2014
35
Cypress, TX
Yep...just ordered some. Also, I just finished putting in the borax. No one ever suggested this, but I highly recommend pouring the fine powder with your back to the wind! Live and learn.

One more question, any waiting period before swimming after adding borates?
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
A higher borate level will inhibit algae more. As you can see in Table 18 in this link, the amount of borates to inhibit algae varies by species where for Scenedesmus subspicatus, 50 ppm roughly cuts down the algae population by 50-70% (over 72 hours) but 100 ppm cuts it down by 90-100%. Of course, this is without any chlorine so with even a little chlorine 50 ppm is probably sufficient to inhibit a lot of algae growth. It's not enough to completely stop algae if chlorine gets to zero, but would certainly slow it down a great deal.

They probably recommend the higher borates level for pools that get to zero chlorine so they won't get algae growth. At 50 ppm, they still might get algae eventually, but again only if the chlorine got to near zero. For anyone maintaining chlorine levels, they wouldn't get algae even without borates, if their FC/CYA ratio was appropriate.