# How many gallons is my hot tub.

#### Mjwall82

##### Active member
I'm in the beginning stages of a pool build and the process has led me to finding this web site. Having read obsessively to learn about the pool I've learned that I have been taking very poor care of the stand alone hot tub that came with the house we moved into in August. I've ordered some AHH-Some and a TF-100 test kit, downloaded the pool math app and I am ready to get this thing sorted out. But, I don't have any idea how many gallons my Hot tub holds. Can somebody please point me in the right direction to figure out how many gallons this hot tub holds? Thanks so much in advance.

#### YippeeSkippy

Take a look at the bottom of the Old Version of PoolMath (at bottom of this page) and enter in the details in "Calculating Pool Volume" and it will help you right out!

#### Mjwall82

##### Active member
Take a look at the bottom of the Old Version of PoolMath (at bottom of this page) and enter in the details in "Calculating Pool Volume" and it will help you right out!

Does that work for hot tubs as well. With the seats and everything the depth isn't very consistent throughout the tub.

#### YippeeSkippy

ok, skip that although you can get a ball park and then deduct x amount for each seat.

What brand and model do you have? You should be able to find that information within the mechanical panel I would imagine?

#### Mjwall82

##### Active member
ok, skip that although you can get a ball park and then deduct x amount for each seat.

What brand and model do you have? You should be able to find that information within the mechanical panel I would imagine?

The pool math formula gave me 611 gallons. So maybe 500 is a good guesstimate. I'll see if I can figure out the make and model when I get home from work. Thanks for the help.

#### jseyfert3

Bronze Supporter
Do you know what brand/model it is?

How many seats is it? Our 6 seat (5 + lounger) is about 450 gallons.

#### Mjwall82

##### Active member
Do you know what brand/model it is?

How many seats is it? Our 6 seat (5 + lounger) is about 450 gallons.
Not sure what the brand/model is. I'm going to take a look this afternoon. It seats 6. So, maybe around 400-500 gallons.

#### jseyfert3

Bronze Supporter
Not sure what the brand/model is. I'm going to take a look this afternoon. It seats 6. So, maybe around 400-500 gallons.
Likely. For an Ahh-some purge I'd use 450 gallons for figuring out how much to add. Once you do your purge(s) and drain and clean the tub, write down your water meter value. Then refill your tub, taking care to not run other water in your house. When your tub is filled to the manufacture recommended level (halfway up the skimmer for ours), shut off the water then go note your water meter value again. Subtract the original value from the later value to get water volume in cubic feet. Multiply this value by 7.48 to get gallons of water.

Now you have an exact amount of water to use for chemical additions going forward.