You want to keep enough stabilizer to protect your chlorine

thepoolpros.com

In The Industry
Sep 9, 2010
12
coconut creek, florida
Split off of I just added 20 Mule Borax to my pool a week ago. It was fine where it was originally, but has now spawned a whole new discussion that is off topic for the old location. JasonLion

You want to keep enough stabilizer to protect your chlorine levels. 10ppm of stabilizer will protect 1.5 ppm of cl2 from uv destruction. The higher the stabilizer levels, the greater algae prevention you will have. It has similar properties as Borate.


Here is a great article about using Borates

http://thepoolpros.com/borate-chemistry
 

dmanb2b

TFP Expert
LifeTime Supporter
Apr 4, 2009
3,734
NY
Re: Informed noob using Borax!

CYA does not prevent algae. It stabilizes chlorine. Chlorine is the sanitizer that kills algae and should be maintained in an appropriate ratio to CYA. The more CYA in your water the higher the FC level you will have to maintain.


To the best of my knowledge, limited as it might be, CYA does not act similar to Borates. Borates do buffer PH, can prevent alagae and makes you skin feel softer, but it does not protect chlorine from UV degradation and it certainly does not buffer PH or prevent algae.

Go ahead and search this forum....most of our 16,000+ members are here as a result of not understanding the FC/CYA relationship and are frustrated trying to maintain overstabilized pools.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
Re: Informed noob using Borax!

CYA is a pH buffer, just are the carbonate system is a pH buffer and just as borates are a pH buffer. However, CYA is NOT an algaecide. What you read in the Powerpoint presentation was a reference to the Sommerfeld/Adamson study that showed that CYA had minimal effect on reducing chlorine effectiveness against algae -- that is NOT the same as saying that it is an algaecide. However, that study is flawed since they did not maintain chlorine levels and instead used amounts of chlorine that equaled the chlorine demand from the algae samples that were added. Most likely, the nutrient broth for the algae contained ammonia or ammonia-like substances that quickly combined with chlorine to form monochloramine which would be at a level independent of the CYA level (since it does not combine with CYA as chlorine does) to kill off algae.

That presentation also refers to the Pinellas county study that is also flawed, but in more subtle ways that I describe in this thread. Basically, the study didn't look at hypochlorous acid (HOCl) concentration, only at FC and other water parameters. If they did look HOCl, they would have found that it was at least as good a predictor of bacteriological water quality as FC because bacteria are incredibly easy to kill with very low levels of chlorine. So one cannot conclude from the study anything about CYA. There were 49 pools with no measurable FC yet had no green algae and 25 of these had bacteriologically safe water -- in fact, only 4 of the 486 pools had green algae -- perhaps algaecide was being used in some pools which would throw off study results and wasn't a parameter they looked at!

thepoolpros.com said:
Thats what I thought too until I took a few college level chemistry classes
If you know chemistry, then you should read this scientific paper that definitively determined the chlorine/CYA relationship in 1974 (the introduction is readable even if you don't know chemistry well). Since you are an NSPF CPO instructor, you should also read the Certified Pool Operator (CPO) training -- What is not taught thread and note its numerous scientific references to published peer-reviewed papers. This isn't just theoretical science either, but has been validated by tens of thousands of pool homeowners, service techs, pool store employees and others at both The PoolForum and here at TFP. The actual algae inhibition levels based on the chlorine/CYA level were first determined by Ben Powell who created The PoolForum and PoolSolutions websites.

Richard
 

anonapersona

TFP Expert
LifeTime Supporter
Nov 5, 2008
2,598
Re: Informed noob using Borax!

thepoolspros.com, I read that entire presentation. First, I was disturbed that most of the data seemed to be from studies from the early 60's, but for one slide later in the presentation dated 1994 and 97. That they grouped data for pools with CYA levels at 20 along with pools with CYA levels up to 100 is crazy.

Hmm, this is interesting... look at slides 34 and 35. Slide 34 shows 486 pool total. In the next slide, they focus on only 332 pools. I have to wonder why they dropped the rest of the pools. Either they had chlorine levels above 5 ppm, or maybe they had such bad bacterial levels that they had to be tossed out to preserve the data. In either case, the fact that of all the pools on slide 35 only 87% could pass a bacterial test is quite disturbing to me. That says there is something fundamentally wrong with the way these pools are being managed.

I know I stopped swimming in the local neighborhood pool after doing laps with a mask and snorkel. I could see so much snot floating around that suddenly I realized why each spring, at the start of swim team, the entire neighborhood came down with sinus infections and such. Poor sanitation in the pool.
 

thepoolpros.com

In The Industry
Sep 9, 2010
12
coconut creek, florida
thank you for the great info. The main reason I wanted to join this site.

Chem Geek, i never said that CYA was a strong algacide, I just said it can be used as one. Because its effects when combined with Amonia and chlorine, whcih will create a type of a chloramine, which is a weak algacide.

In Florida, I dont recommend any copper, or amonia based algacides because of the turmoil it presents to the water with stainign and combined chlorine. It is actually cheaper in the long run to use just HOCl and protect it with CYA.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
That's great. Welcome aboard. You might look at my responses to some of your other posts as there is more info there. Please don't take offense -- I just wanted to correct some misconceptions and I could have misinterpreted some of what you were saying.

For example, as I note in this post, your FAQ Pool Algaecides promotes Lo-Chlor algaecide which contains chelated (complexed) copper. Yet you write above that you do not recommend copper-based algaecides so I'm confused. Perhaps some of the info on your site comes from different sources or is out-of-date and not consistent.
 

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