Accurate Calculations CYA and Pool Volume

[onemorekat]

I've slammed my pool according to CYA/Chlorine Chart wity CYA around 50 for a SWG and would like advice for further maintenance...

*My pool isn't exactly square nor round nor oval...it could differ between 13,000 and 23,000 per calculations; 20'Wide 30'Length Approx. 3' Shallow and 7' Deep end.

Photos attached.

*CYA reading - Is the reading taken at the almost cannot see black dot, mostly cannot see black dot or really cannot see black dot as values differ greatly?

Thank you very much for your help so far and for this forum!!!

onemorekat in Florida

 

[borjis]

I would go with the lowest one where you cannot see/just barely make it out....just be sure that it could be seen if there was just a little less fluid in it.

and it helps to look away then look at the dot then look away again.

also one key thing, has to be in full sunlight with your back to the sun, holding it at waist level with your body shading the tube.

that looks like an indoor photo and won't be nearly as accurate.

You can get a better grasp of your real pool volume by using the poolmath calculation sheet.

maybe try it with chlorine and calcium additions. (if your calcium isn't too high)

It will estimate and rather quickly you will realize your actual volume.

My pool for example was unofficially documented as 17,000 gallons when i bought the house.

no way...it was actually 13,000 gallons which I figured out with pool
math and when I filled it after a new liner was installed. I calculated this based on how long it took to fill a 5 gallon bucket to the brim
and how many hours till it was filled and this further verified the actual volume.

 

[Texas Splash]

Using the Poolmath calculator and inserting 20x30 w/ average depth of 4.5ft, I got just over 20K gallons. You could start at 20K, then adjust that number up or down based on the results you see from testing target/goals reach form the amounts of chemicals added. Based on 20K, if you shoot for a TA of 60 and go to 70, you estimated gallons is too high.

As for CYA, I agree with borjis. The 3rd photo is the closest to what you want - totally gone when viewed. Once you take a first reading, give your eyes a quick break. Pour back to the mixing bottle then to the tube and try again. Do it 4-5 times if needed to get a good feel and average reading.

Regarding your SLAM and CYA ... if you are done and passed a SLAM, make sure you increase CYA to at last 70 for a SWG pool. It needs to be that high to protect the FC produced. Hope that helps.

- - - Updated - - -

Oh, and don't forget to update your signature with all of your pool info.

 

[ned8377]

I agree with what borjis said and would add that it doesn't matter, so much, about the size of your pool. When you can't see the dot outside, in the sun, is how much CYA you have in the water. You should wait at least 4 days before you add anymore because it takes a while to mix into the water.

 

[borjis]

Based on your shape and depths and your pool being roughly the same dimensions/depth as mine I would guesstimate your pool is around 18,000 gallons.

 

[pooldv]

Welcome to TFP!

Here are some reference pics on the Taylor website.
https://www.taylortechnologies.com/ChemistryTopicsCM.ASP?ContentID=36

 

[onemorekat]

Thank you for so many helpful tips! I can now add a working signature