I think I'm wrong on my pool volume...help!

[Cherie]

I thought our pool was about 19,000 gallons, but am now questioning that. I've attached a link showing the end of the pool build and how our deep end was made. You can see from the picture that we have a 3' "ledge" all around the deep end. The pool is 16x32 4' deep in the shallow end and 7' deep in the deep end. But the 3' ledge around the deep end is throwing me off. I can't seem to figure out the volume in the deep end.

The reason I'm questioning this now is because I've noticed that when I follow the Pool Calculator, I end up with much higher ranges than I anticipate. The other day, my readings were : FC 3.5; CC 0; pH 7.4; CYA 30

I wanted to raise my FC to about 7. So I input 19,000 gallons and set my goal from 3.5 to 7.0. I put 1 gallon of 6% in at 6pm, which should have raised a 19,000 gallon pool from 3.5 to 7.0. However, at 8:30pm, my FC was not 7.0, but instead was 8.5. So when I plug those figures in at the bottom of the Pool Calculator, it reflected that I have a 12,000 gallon pool, which I know is wrong.

Can someone take a look at how they did the deep end and help me figure out for sure about how much water is in our pool? I'd like to be more accurate on how much bleach and muratic acid I need. At first, I had 21,100 gallons. THEN, I realized I needed to adjust for the 3' ledge around the deep end, as well as the slope from the ledge to the bottom. SO I changed it from 21,100 to 19,000. I'm not good at math....please help!!

I've posted our pool build on here before, but can't find it now to just paste in this thread. So I hope the new link works.

Thanks! )

http://s586.photobucket.com/albums/ss30 ... mview=grid

 

[JasonLion]

I get various numbers, depending on assumptions, from 16,000 to 17,000 gallons.

 

[PaulR]

It's a little hard to tell from the pictures but it looks kind of like you don't have so much a deep "end" as a deep "middle". Is that a reasonable description?

In that case what I'd do is pretend you had two pools: a 16x32 4' deep flat-bottom pool, and then another 3' deep pool with whatever dimensions that deeper section is. If that deep section is, say, 10x20, then your volume is
(16x32x4) + (10x20x3) = 2048 + 600 = 2648 cubic feet
and 2648 x 7.48 = 19,800 gallons. This will overestimate a bit because the deep section doesn't have vertical walls, they slant. But it should be fairly close.

--paulr

 

[Cherie]

OK guys. Thanks for the help. The "deep middle" measures 10x10x3 with sloping. So adjusting for sloping, I came up with 17563 ----> 17,000 gallons. Thanks a bunch!