New owner, need help with ratios of chemicals to water

[egabe1]

Hello,

My wife and I purchased a home last year with an IG swimming pool, 20'x40' from 3ft to 8ft deep.
I just finished draining, acid washing, and epoxy painting our pool. We are ready to re-fill and I would like to maintain our pool using the BBB method.

I'm sure it is listed here somewhere, but I am looking for the ratios of cyanuric acid, bleach and borax I will need to add to a roughly 35,000-40,000 gallon pool.

Our water is provided by the city from which they pump from 3-4 different wells and then distribute.

I am ordering the K-2006 test kit that it seems everyone recommends.

Again, I am new and have started searching through some of the threads trying so learn from others, but any advice is always welcome.

Thanks

[aylad]

You will need cyanuric acid to approximately 40-50 ppm, bleach for chlorination (1 gal of 6% bleach will add approx. 1.7 ppm of chlorine to a 35K gallon pool), and Borax is only used if you need to increase your pH or increase your Borate level for a little added algae protection. There's really not much way to know how much you'll need until you test your pH level. Does your well water have metals? That's gonna be a really important thing to know when you refill it....

Welcome to the forum!!

[PoolDoc]

Hi egabe

For starters, let's check your pool volume. If your pool were 20 x 40 x 8' uniform depth, you'd only have 47,000 gallons. If it were 1/2 3' deep and 1/2 8' deep (straight drop to 8' at the midline), you'd have 33,000 gallons. I'm guessing you have a vinyl pool (those particular dimensions are typical of liner pools, more than concrete or fiberglass) and 20 x 40 vinyl pools with a deep end typically run in the 28,000 - 30,000 gallon range. That's a big enough error to matter.

Oops. Just checked -- you have done the chart, and have a FG + concrete pool. If it's a straight rectangle with a bowl shaped hopper, and the break at the midline, you are probably closer to 24,000 gallons. (Assumptions: 3' water depth through out shallow area; rounded bowl hopper; shelf under FG wall, along pool edges.)