# How many gallons is my pool?

#### Shelley N

##### Well-known member
I've never been able to figure it out how many gallons my pool actually holds, so this weekend I tested the CL at 2ppm with the FAS-DPD, added 2 quarts of 6% and it rose to 4.5ppm. I tried to get the bleach calc to work backwards for me, but it wont. How do I figure this out? It's a 15 x 30 AG and I've heard so many different amounts of what it holds that I just thought I'd measure the rise after adding. Thanks.

#### The Mermaid Queen

TFP Expert
Download BleachCalc here... it has a calculation that does it for you. If your water (not wall) is 3.5' deep, you have 9276 gallons. If you water is 4 feet deep, you have 10,602. If you have a deep end, you will have to find the avg. depth for your calc.

EDIT... just plugged in 10600, 1/2 gallon, and it said you should have gotten a 2.8ppm rise in TC, which is near your 2.5... I'd say you have around 11,000 gallons.

#### Shelley N

##### Well-known member
Forgot about the "other calcs" button.

Today, it's 44", so that's 3.66', so that's 9700.83 gal.

Golly, I thought it was more since the bleach calc says to add 2 quarts to raise 12,000 gallons 2.5ppm. That was the rise in ppm I got by adding 2 quarts anyway.

#### Shelley N

##### Well-known member
If I use the Pentair pool calc program and enter a 15' circle and a 15' square (which a 15 x 30 oval is I think) i get 11,026 gal. That's quite a difference.

#### The Mermaid Queen

TFP Expert
This is just weird! I used the pentair and did the oblong, and just used 15 feet for both diameters, and 3.6 depth, and got 10,935.
When I added up the 7.5 radius circle plus the 15' square, I got 10,846... different than the numbers you got.

Personally, if it was my pool, I would treat it as 10,000, and then adjust a little accordingly, if necessary.

#### Shelley N

##### Well-known member
I used 3.66 for my depth and that's the difference.

Thanks for everyone's input.

#### giulietta1

In The Industry
I've recently figured out that I have probably overestimated my pool gallonage. . . I don't know the manufacturer, but I have some documentation showing that the deep portion is 4'3" and the shallow part is 3'3". I assumed that meant the depth of the filled pool, but once I actually got into the pool, I realized it wasn't that deep! So those dimensions actually refer to the depth of the shell, not the water.

I recalculated with revised depths (30" and 42") and obtained gallonage figures around 7500-8200. Shucks, now I have to use a calculator to figure out how much chemicals to add! 10,000 gallons was so easy to work with <sigh>

Jules