Calculating exact pool size

[PabloS83]

Need some help in figuring out the pool size as every calculator I put the dimensions in say our pool is about 43k gallons but our pool guy swears it’s only 32k.

Trying to do this as he’s become unreliable and missed last week so now I have a cloudy pool with no chlorine and a low PH. I figured I can at least start to see what I can do on my own. Regretting now doing the salt conversion now but not too late to get that done.

So what do I have here? 43k gallons or 32k gallons?

Also looking into getting the following SWG but looking for some feedback on the brand/model if someone has any???

CircuPool Universal55 Saltwater Chlorinator | Discount Salt Pool

www.discountsaltpool.com

 

[Texas Splash]

I'm getting about 33,400. What you can do is split the different and go with about 36K or so in the PoolMath APP. When you go to add chemicals and expect a specific result, you can tell later if the pool volume was off. If you over-shoot your chemical goal, the volume was too low. If you don't meet your goal, the pool volume was too high.

 

[PabloS83]

I'm getting about 33,400. What you can do is split the different and go with about 36K or so in the PoolMath APP. When you go to add chemicals and expect a specific result, you can tell later if the pool volume was off. If you over-shoot your chemical goal, the volume was too low. If you don't meet your goal, the pool volume was too high.

Hmm how do you get that #? Is it the slope I'm not accounting for? When I put in 37' x 24' and the depth's, it comes back at 43k???

Pool Volume Calculator | Pool Maintenance

Enter your pool shape, length, width, shallow- and deep-end depths into our Pool Volume Calculator to find your pool's volume in gallons. Learn more about pool volume calculator, Visit SwimmingPool.com

www.swimmingpool.com

 

[Texas Splash]

Hmm how do you get that #? Is it the slope I'm not accounting for? When I put in 37' x 24' and the depth's, it comes back at 43k???

I used the calculator on the old Poolmath (Web) version. Link in my signature. It's a bit subjective of course as we try to estimate average volume across the slope and other areas. Unless you check your water meter before & after a fill, there's going to be some variances. But adjusting the volume as you add chemicals will help you get quite accurate over time.

 

[Rancho Cost-a-Lotta]

As Pat said, it's somewhat subjective, but this is what I get.

37x19x6.5=34,200 for the main section. (depth avg. of 4 and 9=6.5')

13X8X3=2,300 gallons for the small section. You can make adjustments here for steps?

Total ~36,500

Also looking into getting the following SWG but looking for some feedback on the brand/model if someone has any???

CircuPool Universal55 Saltwater Chlorinator | Discount Salt Pool

www.discountsaltpool.com

Follow this thread regarding the CP Universal 55. Also see Post 32 in the same thread. Looks like the same unit for less $.

SWG ratings

Hi all - I installed an SWG (Circupool Universal 55) this year and am finding I have to run it a bit longer than I was expecting. Through May and June I usually go through no more than 2ppm FC daily. This year with the SWG if I am doing the math correctly, I’ve been going through 3-4ppm...

www.troublefreepool.com

 

[PabloS83]

I used the calculator on the old Poolmath (Web) version. Link in my signature. It's a bit subjective of course as we try to estimate average volume across the slope and other areas. Unless you check your water meter before & after a fill, there's going to be some variances. But adjusting the volume as you add chemicals will help you get quite accurate over time.

Thanks! Just wanted a second opinion

 

[flynwill]

I get 37,100. But I'm making an assumption about your drawing, that corners of the pool are square and the 27' annotation on the left is the whole width including the 3'x5' section (is that steps? I'm assuming so and guessing average of 2' deep there)
Break the problem into parts. You have a
24' x 13' x 4' deep shallow end = 1248 cu ft
7' x 3' x 2' deep steps = 42 cu ft
10' x 19' x 6.5' sloped area = 1235 cu ft (the 10' is a guess from your drawing)
14' x 19' x 9' deep end = 2394 cu ft
Total 4191 cu ft = 36,794 gallons.
This estimate is high as it doesn't account for the radius curves in the bottom corners. If I take 6" off all of the depths to account for the rounded corners the total drops to about 34k gallons.

 

[Ibelyle]

Is 4' the depth of the pool, or depth of the water in the shallow end. Most vinyl pools are only 40" when filled to half way up the skimmer/s face?
Then calculate the surface area of the pool. I would estimate a small deduction for radius corners, but you can use the radius to calculate the volume of a cylinder, which would account for at least four of the corners.
Once you have the total surface area, multiply by the shallow water depth of the pool to get the cubic feet (x 7.5) and the gallons of that portion.
Next determined the depth of the "hopper" i.e. from the base of the wall to the top of the main drain cover. Once you know that depth, the you can calculate the volume of the rectangular column and six abutting wedges that make up the hopper. Some vinyl pool bottoms closely follow the sharp transition lines shown in the plans. Other installers, "dish" those transition lines. Also, some builders over dig the deep ends so that the liner stretches more. However, if you stick with the liner dimensions shown on the plan, you will end up with an amount of gallons which is more than accurate enough for calculating chemical amounts and sizing equipment etc. Good luck.

 

[IceShadow]

There's a method of calculating the pool volume using chemistry. It involves testing the TA to the nearest 1ppm and then adding a set amount of baking soda, then testing TA again after mixing well. But you don't really need that level of precision - just dial it in with chemical additions. If you add FC and the FC tests right after you add as higher than expected, lower the pool volume. If it's lower than expected, raise the pool volume.

 

[JamesW]

A = 19 x 13 x 4 = 988 cubic feet

B = 19 x 8.6 x 6.5 = 1,062

C = 19 x 15.5 x 9 = 2,650

D = 5 x 13 x 4 = 260

E = 7 x 3 x 4 = 84.

Total cubic feet = 5,044.

Gallons = 5,044 x 7.48 = 37,729

 

[JamesW]

24' x 13' x 4' deep shallow end = 1248 cu ft
7' x 3' x 2' deep steps = 42 cu ft
10' x 19' x 6.5' sloped area = 1235 cu ft (the 10' is a guess from your drawing)
14' x 19' x 9' deep end = 2394 cu ft
Total 4191 cu ft = 36,794 gallons.

Total = 4,919 x 7.48 = 36,794.

I suspect that the volume is in the 34,000 to 37,000 gallon range.

Are you sure that the depth is 9 feet?

 

[JamesW]

If we assume the slope is 11 feet long, the volume is slightly less.

A = 19 x 13 x 4 = 988 cubic feet

B = 19 x 11 x 6.5 = 1,359

C = 19 x 13 x 9 = 2,223

D = 5 x 13 x 4 = 260

E = 7 x 3 x 2.5 = 52.

Total cubic feet = 4,882.

Gallons = x 7.48 = 36,517

Are you sure that the actual water depths are 4 feet and 9 feet or is that the depth from the top of the coping?

 

[JamesW]

This thread from last year said 10 feet deep.

A vinyl liner pool is normally only 8 feet deep and 9 or 10 feet deep is highly unlikely especially for a pool that is only 37 feet long.

Do you have a diving board?

Measure the actual water depth in the deep end and the shallow end.

Do you have a picture of the pool?

Can someone help me figure out amount of gallons?

Perhaps I did that calculations wrong but, I did 27' x 37' x 7 = 6,993 but the pool is pretty large and that number seems a bit off to me.

www.troublefreepool.com

 

[JamesW]

The depths are likely 3.5 feet and 8.5 feet.

A = 19 x 13 x 3.5 = 865 cubic feet

B = 19 x 11 x 6 = 1,254

C = 19 x 13 x 8.5 = 2,100

D = 5 x 13 x 3.5 = 228

E = 7 x 3 x 2.5 = 53.

Total cubic feet = 4,500.

Volume = 4,500 x 7.48 = 33,660 gallons.

 

[JamesW]

If the depths are 3.5 feet and 8 feet.

A = 19 x 13 x 3.5 = 865 cubic feet

B = 19 x 11 x 5.75 = 1,202

C = 19 x 13 x 8 = 1,976

D = 5 x 13 x 3.5 = 228

E = 7 x 3 x 2.5 = 52.

Total cubic feet = 4,323.

Volume = 4,323 x 7.48 = 32,336 gallons.

 

[Ibelyle]

A = 19 x 13 x 4 = 988 cubic feet

B = 19 x 8.6 x 6.5 = 1,062

C = 19 x 15.5 x 9 = 2,650

D = 5 x 13 x 4 = 260

E = 7 x 3 x 4 = 84.

Total cubic feet = 5,044.

Gallons = 5,044 x 7.48 = 37,729

View attachment 421803

I'm not going to attempt a calculation w/o a floor diagram detailing all transitions for the hopper. However, typical liner specs for rectangular pools result in +/-: 16x32 @ 18K gallons; 18x36 @ 24K. gallons; and 20x40 @ 28K gallons. Even with the shallow end extension, and allowing some variation of the floor pattern, I find it difficult to estimate this pool at more than 30K, if that.

 

[JamesW]

If the depths are 3.5 feet and 8 feet.

Volume = 4,323 x 7.48 = 32,336 gallons.

It's hard to say without pictures and the exact diagrams.

The hopper will have sloped walls and that means that the depth at 8 feet is only a fraction of the deep end.

Possibly in the 30,000 to 32,000 gallon range.

 

[JamesW]

27,100 + 1,700 for the extra = 28,800 gallons.