borax over the winter to fight algae

[fuelman]

I'm gonna super chlorinate before closing and I'm wandering about adding Borax to fight the algae next year. I have read that I need 50PPM. Is there anything I should know or be warned about?

[aylad]

Just keep in mind that as you add Borax, your pH is going to rise, so to counter that you'll need to add muriatic or dry acid.

Janet

[waterbear]

The ratio is 60 oz borax by weight (3.75 lbs)and 30 oz of muriatic acid by volume (2 oz short of a quart) to raise each 1000 gallons to 50 ppm. Remember that 20 Mule Team comes in 76 oz boxes (4.75 lb)! Figure out the total you will need of each and then add half the acid and then broadcast (sprinkle) half the borax into the pool, brush to mix well then repeat with the remaining half of acid and borax. Circulate for 48 hours, test pH and adjust to 7.6 if it is higher than that.

If you don't mind spending the money you can also buy Proteam Supreme Plus (a mixture of sodium tetraborate pentahydrate and boric acid) which is pH neutral but pricey!. You need about 3 lbs per 1000 gallons to reach 45 ppm which is close enough. If you want 50 ppm you will need 3.35 lbs per 1000 gallons.