Pool Volume Question

[Karl]

Any math wizzes out there? I'm curious to get a more accurate figure about how large my pool is in gallons. I just added 80 pounds of salt to the pool which increased my salinity by 560ppm. With these known facts, I should have enough data to be able to calculate my pool volume I think.

Thanks in advance for any help!

 

[Leebo]

Don't forget the pool calculator has a "Estimating pool volume" section. ;D Should give you a very close idea on your gallons.

 

[Leebo]

ps.....it looks to be around 5 feet deep.....and holds about 17000 gallons.

 

[Karl]

Thanks leebo, I saw that too. Just trying get a better estimate by using another method :study:

Appreciate that fast reply!

 

[duraleigh]

The accuracy of salt test strips is +- 400ppm if that's what you used. A salt drops test is usually +- 200ppm. Digital salt readouts are worse than both of those.

 

[linen]

Okay you baited me into it: adding exactly 80 lbs of salt to get 560 ppm at 80 deg. F, I get 17178.59 gallons.

Of course those bags are not exact weight and there are some impurities in them. Assuming perfectly pure salt, but a +/- 2 lbs per bag (I am assuming each bag is 40 lbs), that gives a range of as low as 16319.66 gallons or as high as 18037.52 gallons...not too bad but...as duraleigh stated your test approach is also inaccurate...a +/-400 ppm means your pool could be as low as 10020.84 gallons, and as high as 60125.06 gallons ...

combining both of those error sources gives the estimate:

9519.8 gallons
to
63131.31 gallons



I think you are better off estimating by doing measurements.

 

[jblizzle]

:lol:

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone

 

[Bama Rambler]

The best way to get a close estimation of the volume is by keeping track of many chem additions and keep adjusting it in the pool calculator until the amount of chems it suggests causes the exact change expected. One or two additions aren't enough to be accurate because of the variability in the chems and measurements.

 

[Karl]

Thanks for everyone's replies ... seems that no matter what, there is going to be a huge variation short of using the measuring tape.

Apreciate everyone taking the time for feedback! Thanks

 

[JasonLion]

There is still a huge variation even when using a measuring tape, unless the pool is exactly rectangular, and even then the water depth varies over time so no number is ever exact.

 

[CyclingCraig]

Another option is to download Google Sketch-Up.

Measure your pool, and model it in Sketch-UP... it has a Volume calculation for objects.

That is what I did since I have a deep end with sloped walls. Original owners said pool was 35,000 gallons.

After measuring with a tape measure and modeling in Sketch-up.. turns out pool is 27,000

-Craig