Pool size and volume

Jump to latest Follow Reply
Ashtro1969

Ashtro1969

Member
May 7, 2020
18
Jacksonville, NC
My first question post!

How accurate does one need to be when calculating pool volume? How far off can it be +/- and still be close enough?

I had my pool cleaned by a pool cleaning business about 3-4 weeks ago. When he was cleaning it, he paced off the measurement and calculated the volume to be around 23k - 25k gallons (I forget the measurements he paced off though). When I received my TF100 test kit last week, I took out the tape measure and measured the pool to be 40x20 (40' 4" x 20" 4" to be exact, but not sure how much the 4 inches matter).

It's a rectangular pool except at the corners and it is 3.5' to 8' at the deep end. However, as can be seen in the picture I attached, the deep end is not exactly 8' deep all around. It starts to slope inward at the wall at 42" down from the top of the pool and the slope goes in 4'. Plugging in the numbers at 40 x 20 in a volume calculator, it equals 34.5k, which is a far cry different than the 23k -25k range I was told. Now, I am not sure if he accounted for the sloping at deep end or not, and maybe that is where he came up with the 25k number, but I do know a +/- 10k difference is something that could mess with the pool math when measuring chemicals and such (at least I think). Also, I am not sure if if adding the 4" on the measurements (40' 4" x 20' 4 ") is necessary either.

Is 34.5k gallons for volume a close enough number to use in the pool calculator app, or do I need to be a bit more precise? I have 34.5k as the volume on the app and have been using that while learning to use it.
 

Attachments

  • 20200517_193029.jpg
    20200517_193029.jpg
    419.1 KB · Views: 9
You'll want to get more precise so you don't overshoot your target when adding chemicals. For chlorine, it could fade your liner to add too much. For pH, dropping too low can do other damage.

I would probably split the difference as a starting point and see how the chemical additions match up to the target or follow the directions in the thread A Chemical Way of Calculating Pool Volume.
 
gonfishin said:
You'll want to get more precise so you don't overshoot your target when adding chemicals. For chlorine, it could fade your liner to add too much. For pH, dropping too low can do other damage.

I would probably split the difference as a starting point and see how the chemical additions match up to the target or follow the directions in the thread A Chemical Way of Calculating Pool Volume.
Click to expand...

gonfishin said:
You'll want to get more precise so you don't overshoot your target when adding chemicals. For chlorine, it could fade your liner to add too much. For pH, dropping too low can do other damage.

I would probably split the difference as a starting point and see how the chemical additions match up to the target or follow the directions in the thread A Chemical Way of Calculating Pool Volume.
Click to expand...

Thanks for the advice. Generally, I am the type of person that prefers accuracy over guesstimates, but in this case (at least for now)I think I am going to split the difference as suggested by yourself and mknauss and go with the 30k (as suggested by mknauss), as it seems to be a good split. It's not that I am not willing to try the chemical method for determining volume, or doubt that I can do it. However, after reading it over, I do not know if I can even perform this test with the TF100 kit supplies, and even if I can, my brain is kinda overwhelming itself with all the information I am taking in from reading on this site, and trying to figure out what/when/how, and all the other questions I have thus far. How to ask them, when to ask them, in what order, and the like. I also have a ton of other stuff going on with being a new homeowner to add to it as well, so it's been hard to focus on the pool as much as I'd like too.
 
  • Like
Reactions: gonfishin
mknauss said:
Welcome to the forum!
Use 30K in the app to start. See if that makes sense when you add your chlorine or acid.
A more exact method is doing what Sue says above.
I suggest you read ABC's of Pool Water Chemistry.
Click to expand...

Thanks for the advice. I just noticed you and I share the same name irl. Greetings fellow Marty!

I am going to go with the 30k as you suggested because of the reasons I explained in my reply to gonfishin. I have read and reread the ABC's a few times and get the principles fairly well. I have also perused the other pool school articles as well. It's just wrapping my head around it all that seems to be the problem. I have way many more questions about the pool and equipment that I am having a hard time knowing where to start. I started with this question because my thinking was that water voIume can obviously affect the amounts of chemicals used/needed. I think that focusing on the pool water chemistry and getting it balanced seems to be the way to go, before asking questions about my equipment and the like (the SWG and sand filter for example,). But even then, I have so many questions in regard to how other things like how like other environmental conditions affects the pool; things such as water level, rain, critters such as frogs and bugs, tree debris, how often this and that et al. Not that it is overwhelming, but it is definitely been daunting to me all things considered.

That all being said, I am going to go ahead and post the results of my weekly test (done this morning) on a post in a few, and also plug the results into the pool calculator app as well (using the 30 k) and see what it says about where I am right now water wise.
 
  • Like
Reactions: mknauss
Ashtro1969 said:
Thanks for the advice. Generally, I am the type of person that prefers accuracy over guesstimates, but in this case (at least for now)I think I am going to split the difference as suggested by yourself and mknauss and go with the 30k (as suggested by mknauss), as it seems to be a good split. It's not that I am not willing to try the chemical method for determining volume, or doubt that I can do it. However, after reading it over, I do not know if I can even perform this test with the TF100 kit supplies, and even if I can, my brain is kinda overwhelming itself with all the information I am taking in from reading on this site, and trying to figure out what/when/how, and all the other questions I have thus far. How to ask them, when to ask them, in what order, and the like. I also have a ton of other stuff going on with being a new homeowner to add to it as well, so it's been hard to focus on the pool as much as I'd like too.
Click to expand...

If you find you're overshooting at 30K when you add chlorine, drop by 1K and see if that works. Or if you find you're coming up short, add 1K.

When I started, I was told my pool was 10K. As I've worked with the pool using TFP methods, I've discovered it's closer to 9600. Not a huge difference, but enough that I believe I caused the bleaching of my liner versus the sun doing it.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply