I am starting to question how many gallons our new IG pool is. It is an 18' x 38' free form with a surface area of 640.1 square foot. The shallow end is 3' and the deep end is 8'. The engineer's drawings indicated that the volume is approximately 23,000 gallons but I'm not sure that is accurate. We just added 182 oz of 6% bleach and it raised the FC from 0 to 5. Using the pool calulator, that increase corresponds to roughly an 18,000 gallon pool. We also just added 8 pounds of 100% CYA. I will test the CYA levels a week from now using the TF Test kit and see what the level is. If the CYA level turns out to be around 50, is it safe to assume that my pool is around 18,000 gallons instead of the 23,000 gallons that I though it was? I am trying to back into the pool size by knowing what effect a given amount of chemicals has on the water. Will this work?
I looked at this a different way by calculating the volume of the 3' deep shallow end across the entire surface area of the pool (640.1SF x 3FT x 7.48 GAL/CF = 14,364 gallons). Is it reasonable to assume that the deep end adds another 3,636 gallons to bring the total up to 18,000 gallons?
Thanks in advance for any comments or advice.