Re: The Great Tetraborate Experiment!

Originally Posted by
vgg659
I will soon install a SWCG, and am very interested in this experiement.
To verify, my optimum target readings should be...
TA 80-90 ppm (before stabilizer correction)
TA 70 ppm (after stabilizer correction)
CH 220-250 ppm
Borates 50 ppm?
Correct? Am I missing something?
Every pool is different and your calcium level is also important in where your TA is. Stabilizer correction will subtract between 20-30 ppm from your TA, depending on your CYA level so you want to have your TA between 80-110 uncorrected or between 60-80 corrected. (The borates also add a bit to your uncorrected TA.
Keep the pH at 7.6-7.7.
Borates between 30-50 ppm.
Calcuim should be slighly higher if you run the TA lower. If your TA is at the higher end then run the calcum arourn 220, if your TA is at the lower end then run the calcium higher (300 or so). If your calcium is higher because of your fill water or new plaster then you can get away with running your TA at the low end. (maybe as low as 70 uncorrected.)
I have not plugged these values into Richard's spreadsheet but from my experience with my customers pools they work! It's a pool, not a recipe for Angel Food Cake!
Every pool is different. Get the system up and running and get the borates and pH in range. See where your calcium is to get an idea of how low to go with your TA. If your calcuim is on the low end put your TA around 90-110 before stabilizer correcton and see how your acid usage is, then lower it about 10 ppm at a time and see if the pool becomes more stable. If your calcium is high (above 300 ppm) start your TA at about 80 uncorrected. I have found that if you add acid as soon as the pH hits 7.8 and bring it back to 7.6 you will have much less acid usage than if you let it rise higher. A vinyl or fiberglass pool is going to be much more pH stable than a plaster pool in any case.you will find a point where your pool seems to 'lock in' to a pH around 7.6 or 7.7 and stay there for a while. It will climb but not as fast.
Retired pool store and commercial pool maintenance guy.
Bookmarks