Please, help me understand the TFP way and why anyone would want to work on their pool daily?

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
48,651
Tallahassee, FL
Your CYA is what holding you back now. You can third the CYA test and see what you find but it gets harder to get a true reading when you do this. I say drain 1/2 your water and go from there.
 
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NextGallon

Well-known member
Apr 26, 2021
65
Virginia
Pool Size
20000
Renting Home Depot, buying harbor freight. Me? I think each pool owner needs a pump to have just in case they need it.
HF has a Drummond 2000 gph submersible. That’s the sort of thing I would be looking for, correct? I shut everything down while I drain and not turn back on until I refill to skimmer levels, right?
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
2,392
Chandler AZ
Pool Size
12300
Surface
Plaster
Chlorine
Liquid Chlorine
Before you start draining....
Mix 2 parts tap water and 1 part pool water. Use this as your water sample and multiply the result by three. Or use 3 parts tap water and 1 part pool water and multiply the result by four. Just be VERY precise with your water measurements as doing a diluted test inherently adds more possibilities for error. The more you dilute the pool water, the less accurate the test becomes.

If you were to drain 1/2 now and your starting CYA was 300, you would still have a CYA of 150 when done refilling. And you just added 10,000 gallons of water to get to only 150. Then you'd need to drain 1/2 again and refill to get to 75-ish. That's 20,000 gallons of refill water. If your CYA was 300 and you drain 3/4 and refill, that would only be 15,000 gallons of refill water to get to CYA 75. Don't waste time draining until you have a better idea of what your actual CYA is.

As for a pump for draining, many rent from from Home Depot or similar. You can also buy one, but those don't pump a lot of water per minute or are expensive. Last I checked, HD was around $50 to rent a sump pump to empty your pool.
 
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NextGallon

Well-known member
Apr 26, 2021
65
Virginia
Pool Size
20000
I am doing cya test under cover as part of our pool deck is under a three season room. So it’s a little bit dark. Might try on the other side of the pool where there is no cover, as I just read lighting matters.
 
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CraigChing

Gold Supporter
Jun 15, 2019
147
Plymouth, Minnesota
Pool Size
22000
Surface
Vinyl
Chlorine
Liquid Chlorine
You should perform the CYA test in bright sun, your back to the sun, CYA tube held at your waist. Fill to level (100, 90, 80, etc.) then hold at your waist, and glance. If you see the dot, fill to the next level and repeat. If you don’t see the dot, your number is the last level where you did see the dot clearly. You can pour the solution back into the bottle and try again to be sure.
 
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zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
13,802
Houston, Texas
The CYA test maxes out at 100ppm. Your pool store's tester probably has 99 as the upper limit if it is an electronic tester. As you have seen, the CYA test is the most subjective of all the tests run on pools and it has a margin of error of +/- 10ppm. When it looks like a member's pool could be higher than 100ppm we recommend a dilution test to get a ball park estimate of what the actual CYA level is.