I will need a little over 170 lbs of boric acid

[LaRockMan82]

After fighting algae problems since Hurricane Katrina I have finally decide to give in and switch over to the BBB method after poaching on this site for the last year. It was the uncanningly accurate depictions of others experience with their local pool store that finally convinced me to switch. It seems they all read from the same script. My pool is about 90K gallons so I will need a little over 170 lbs of boric acid to bring it up to 40 ppm. I have located a chemical supply company that will sell boric acid in 50lb bags for $.85 per lb. Considering I will need little if any acid to balance the ph with the boric acid as opposed to the borax, this seems like the less expensive alternative. Anything I should watch out for? Also I seem to recall a link that listed boric acid for $.69 per lb but forgot to capture the link and now can't relocate it.

Thanks.

Gil

 

[duraleigh]

Re: So you want to add borates to your pool--Why and How

Hi, Gil,

Welcome to the forum. I hate to be such a stick-in the-mud but please do not think that borates will be the magic cure for algae issues. Adequate chlorine levels at all times is the answer for an algae free pool.

Borates are an option that may well enhance the ease of pool maintenance but there is no substitute for the correct chlorine levels (and correct chlorine/CYA relationship)

 

[chem geek]

Re: So you want to add borates to your pool--Why and How

Gil,

As described here and here, boric acid is somewhat more expensive than the combination of 20 Mule Team Borax with Muriatic Acid, but it is more convenient. As Dave noted, borates are optional and do not completely prevent algae growth, but I will say that since I've added them I'm very happy so far with the benefits. I will do a test at the end of the season to see how well they prevent algae growth -- my pool is normally very reactive due to high phosphate (and probably nitrate) levels and warm water temps (86-90F) though the algae has been controlled through proper Free Chlorine (FC) levels relative to the Cyanuric Acid (CYA) level. I screwed up once (before I started using borates) letting the chlorine get to zero and a few days later my pool started to get cloudy (and bacteria had converted some of the CYA into ammonia).

Richard

 

[LaRockMan82]

Re: So you want to add borates to your pool--Why and How

Dave & Richard,

Thanks for the reply. So while its not the magic bullet I was hoping for maybe it will make it a little more forgiving. My plaster became pitted during my extended Katrina vacation and needs to be redone, but its not in the cards for the moment. I have a taylor test kit and my numbers at the end of the day before chlorination are:

CYA 40
FC 1.5
TC 2.0
PH 7.7
TA 70
CH 300

It was same old-same old with the pool store. Pucks, copper based algaecides and everything else in the store that they could throw at me. After stumbling on this site, and I admit was I skeptical at first, I drained and filled to get the CYA back to a reasonable number and started using cal-hypo to chlorinate (hauling that much bleach just didn't seem practical). That in itself resulted in a dramatic improvement, but the water will be fine for months at at time then it seems like any little thing, such as a couple of days of rain, temperature change and sometimes no obvious changes at all will set it off. Cloudy one day and turning green the next. I am hopeful that the algaestatic properties of the borates will temper it enough to make it a little more forgiving.

Gil

 

[chem geek]

Re: So you want to add borates to your pool--Why and How

Your 1.5 ppm FC with 40 ppm CYA is not sufficient to prevent algae growth. You need the minimum FC to be at least 3 ppm and for sure anything below 2 ppm is going to have algae grow faster than chlorine can kill it. The Chlorine/CYA chart will guide you as to the appropriate minimum FC for the CYA level.