If I may jump in, I second the concurrence of the ~45k pool volume estimate. Actually, that's probably high. I say that because, while I have many other things I probably should be doing/have done, I decided instead to take this pool volume question as a challenge, and spent the past few too many hours trying to figure out how to accurately deterimine said volume.
For the tl;dr crowd: only 38,224 total gallons
For those with nothing better to do or live for other than to read the wild ramblings of a mad man, read on!
To begin, with any complex problem, the first step is to break down the problem into smaller pieces. In this case, the difficult part is determining the volume of the "deep" end. And even then, just the pyramid part below the base of the block wall.
Because pics say so much, here is a drawing I created using some sophisticated architectural cad/cam software known as mspaint:
View attachment 83099
The overall measurements, besides those provided in an earlier post, were determined by counting cinder-blocks. It's a little tedious, but accurate. Because, including the morter between them, on average, cinder-blocks are 8" high x 16" long. So, that is the "unit" I used for "measuring" the pool (along with a couple of off-the-cuff-ball-park-gestimations for the depth of the deep end).
Anyway, on to those measurements...
For starters, the cinder-block walls are only 4 blocks high, or 32 inches, ignoring the deck / coping. And the maintained water level will probably be a few inches lower, so the skimmer can skim. So, keeping the estimate a little high, let's say 30 inches (2.5 ft) for the effective water height of the block wall.
Now, for the width, I count 18.5 blocks, which comes to 24.666666667 feet, give or take a few atoms.
For the length, I was unable to find a pic that clearly showed countable blocks for the entire length. So, we'll use the 50' value provided in an earlier post, which is 37.5 blocks. However, I was able to count the number of blocks along the length of the sloping part of the pool bottom: 24 blocks, or 32 feet.
Now, let's get an easy part out of the way, and calculate just the 2.5' depth for the entire pool:
50' x 24.6667' x 2.5'
~= 3083.33 cubic feet
x 7.4805 (gallons per cubic foot)
========
~= 23,065 gallons.
Now for the steps, we'll take 1/2 (the L x W of the steps x the 2.5' water depth):
1/2 x (5.5 blocks) x 6' (per earlier post) x (2.5' depth)
= 1/2 x 7' 4" x 6' x 2.5'
= 55 cubic feet
x 7.4805 (gallons per cubic foot)
========
~= 411 gallons
Now for the "hard" part - the "bowl". Fortunatly, said "bowl" appears somewhat centered in the "deep" end. And IMNSHO, it is no more than 8 feet deep from the pool "surface". But, I'll round to 8 feet from the base of the wall for the next part ('cause that's what I've already drawn in the pic above...).
Ignoring curves etc, the afformentioned bowl of the deep end is basically an inverted pyramid. And the formula for the volume of a pyramid is (I looked it up):
1/3 x (Area of the base) x height
And remember, for the height, we're just measuring from the base of the block wall to the bottom of the deep - our "gestimated" 8 feet.
So: 1/3 x (32 x 24.666667) x 8
= 1/3 x (739.33333) x 8
~= 1971.6 cubic feet
x 7.4805
========
~= 14,748 gallons in the "inverted pyramid" of the deep.
Also note that the pool's actual bottom doesn't go all the way to the "tip" of the pyramid, so that calculation may be a little high. Although, water in all the pipes may make up for that difference, so we'll just assume it does!
And now, (drum roll.....) for the Grand Total:
23,065 + 14,748 + 411 = 38,224 total gallons!
If you get a better measurement of the depth of the bowl *from the base of the wall*, just plug it into the variable D in the following simplified formula for a new estimate:
( 1843.5 x D ) + 23065 + 411
As a final note, all of the above assumes that various assumptions assumed reasonable assumptions.
Hope that helps!
PS: Did your cat photo-bomb one of the pics with the diving board? Or was that an intentional portrait? Either way, good shot!
