Bromine Chemistry Question

[PoolDoc]

Btw, I only added 18 boxes of borax before running out. (I wiped out the shelves at several stores). I tested with the Lamotte strips and it seems to read between 50 and 80. I'm not sure why since I didn't add all the borax called for.

Most owner-reported pool volumes are high. Liner volumes supplied by builders and liner makers are for the OVERFLOW volume, not the actual in-pool water.

[FormerBromineUser]

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Good point. I thought about that too....

When I originally figured my volume I used: 20x40 rectangle with an average 5' 8" (5.66') depth (3.2" shallow, 8.3" deep) to get around 33K.

Then, when we filled this year, I had 4 truck loads of water brought in. One truck supposedly held 5.9K, the other 5.8K. That's almost 24K total. Then I added over a foot with my hose which I calculate added another ~6,000+G. (20x40x1=800ft3=5,948G=~6K) 24K+6K=30K That put me at a revised 30K figure.

Do you think the corner bump-outs (see avatar) can account for that big of a difference? Am I doing something else incorrectly?

[PoolDoc]

Inset corners -- 3' 90 deg radius x 4 => 3^2 * 3.14 * 3.2 * 7.46 = 700 gallon deduct
Steps: 1/2(4' inset * 2.8 deep) * 6 wide * 7.46 = 250 gallon add

Shallow part of pool: 20 * 40 * 3.2 * 7.46 = 19,098 gallons add
Deep part of pool: 20 * 20 * [(8.3 - 3.2)/2] * 7.46 = 7,610 gallons
[Probably should be [(8.3 - 3.2)/3] -- but it depends on the shape of the slope and hopper ]

19098 + 7610 + 250 - 700 = 26,258 total

[FormerBromineUser]

Thanks for the calculations! My kid, a physics major, promises to get an accurate measure of the deep end as soon as he has time. Kids.

PoolGeek: Guess what??? My husband swam for the first time last night after the addition of borates and he says his hair and skin are MUCH better! His hair (what's left of it... tee-hee) was soft, not sticky. His skin, not overly dry or sticky. He said there is a definite difference! He said he loves the "feel" of the water now. Hmmmm.

I am wondering, though, even with a pool of 26K, why it only took 18 boxes of Borax to get my borates over 50 (it still looks to me to be closer to 80). The "recipe" in http://www.poolforum.com/pf2/showthr...stant-to-Algae calls for 10 boxes per 10K. Is there any other test you can run for borates that is more accurate and not cost prohibitive? I'm really puzzled.

[PoolDoc]

1. It looks like I may have an error there; I'm going to have to check because 2 info sources, aren't in agreement.

2. BUT, how were you testing? If it was the AquaChek . . . they are pretty much unreadable. Test some tap water with known borates (0.0) and see what you get.

[chem geek]

It's 7-3/4 boxes (76 ounces weight each) of 20 Mule Team Borax per 10,000 gallons for 50 ppm Borates. To balance the pH, this requires 282 fluid ounces (35-1/4 cups or 2.2 gallons) of full-strength Muriatic Acid (31.45% Hydrochloric Acid). You usually alternate adding back and forth so that you don't have the pH swing too wildly.

I'm glad the feel of the Borates are working out. I think the main effect is a reduction of surface tension and/or a surfactant effect and that may make the hair not stick together as much and the skin feel a little more silky, but quite frankly the effects aren't noticed by everyone and I'm suspicious that some of it isn't just the placebo effect.

[FormerBromineUser]

PoolDoc: I bought the borate LaMotte test strips as recommended. May I test borates with distilled water instead of tap? Our tap is softened well water....

ChemGeek: Your borax/volume ratios agree better with my results although it appears I am testing higher than 50. Maybe Ben can use your ratios to compare with his other "info sources". The placebo effect works for me if it makes my husband happy with my new water recipe: pool forum vs. pool store! But he is ADAMANT about the improvement since adding borax. I can't speak to it; 75 degrees is way to cold for me. I read that you use borates, Richard. Have you gone swimming in water without borates to see if YOU notice a difference? Just a thought.