Reverse engineering pool volume

[Krame]

Hey all.

When you get the recommend addition for a chemical, such as chlorine, where does the calculator try and land your outcome?

For example: I measured 2.0 FC yesterday and I added the recommended amount of chlorine and after 5 hours I got 7.5 FC.

Given my other pool test results, the recommended FC is between 4 and 8. Does the calculator try and push you to the high end of normal? Or does it shoot for the middle?

I ask because I don't actually know how many gallons my pool actually holds. The previous owner wasn't sure, even though he's the one who had it installed.

So if the pool calculator shoots for the middle and I got a high end, then I know my volume is a little less than what I'm currently estimating.

 

[jesse-99]

So if the pool calculator shoots for the middle and I got a high end, then I know my volume is a little less than what I'm currently estimating.

Yes, assuming you added the amount it recommended, and your previous tests were accurate, and after the addition your tests resulted in you overshooting that amount, chance are your pool volume is less than you think. How many gallons do you think your pool might be?

 

[Krame]

Ack. Just saw this thread in the recommended thread list.

Reverse engineering the math

Ok maybe a silly question but I thought I would ask the experts. I have never been sure how many gallons my pool holds. I’ve seen all the various ways to calculate it but my pool is an irregular shape and has an attached hot tub. My best guess is it is about 12000 gallons. I just did a test and...

www.troublefreepool.com

 

[Krame]

Yes, assuming you added the amount it recommended, and your previous tests were accurate, and after the addition your tests resulted in you overshooting that amount, chance are your pool volume is less than you think. How many gallons do you think your pool might be?

I have a 16x32 in ground. There's a shallow side and it tapers down to the deep end. Deep end sides slope down as well such that a child could hold on to the ledge and still get footing.

I was estimating 20,000 gallons, but assuming i did the testing and chemical addition correctly, it's more like 15,500 gallons

 

[UKjames]

A couple of variables to be mindful of in reverse engineering

- whilst the bottle of sodium hypochlorite says 10% it might not be exactly this and so the exact strength of chlorine will be unknown unless you measure it
- if you’ve any ‘load’ in your pool be that algae or other organic matter or just sun light then that will start to consume the added chlorine so you need to do an OCLT too i think