Help Size Pump and Filter and Calculating Gallon Capacity of Pool??

[webfeet]

The brochure states that the pool is 28,017 gallons. By the formula using average depth I get about 35,000 gal (using rectangle shape in calcs) The pool is 40'6 X 20'6" GRECIAN style or very long octagon ( 8 sides) 3 ' deep on shallow and 8' deep on deep end. Are the answers different because the pool is not a rectangle? 7,000 gals seems like a lot of difference to me. I want to select the correct pump and filter size. Would 7,000 gals make a difference? Would like to turn water over every 8-10 hours. Do I need more than 2 returns? May add a water slide and fountain in a couple years and a SWG. Any input is appreciated.

[mas985]

The brochure states that the pool is 28,017 gallons. By the formula using average depth I get about 35,000 gal (using rectangle shape in calcs) The pool is 40'6 X 20'6" GRECIAN style or very long octagon ( 8 sides) 3 ' deep on shallow and 8' deep on deep end. Are the answers different because the pool is not a rectangle?

Yes. Also steps, benches and curves from walls to bottom reduce the volume. I would go by the brochure.

7,000 gals seems like a lot of difference to me. I want to select the correct pump and filter size. Would 7,000 gals make a difference?

11 GPM but again, I would just go with the brochure.

Would like to turn water over every 8-10 hours. Do I need more than 2 returns?

My pool is 21,000 gallons and I have 4 returns. Do I need them? Probably not but they are nice to have. I point 1 downward in the deep end and the other three to provide proper water flow to my two skimmers. Yes it is overkill but it was what I wanted and I am glad I did it.

May add a water slide and fountain in a couple years and a SWG. Any input is appreciated.

Other recommendations:

A large filter will minimize cleaning/backwashing.

A small HP pump will minimize electrical bills. You only need 47-58 GPM for 10-8 hour turnover so a 3/4 HP high efficiency pump is all that is really needed for circulation. However, if you need more power for a spa, water features etc., then consider a two speed pump or multiple pumps. If your not going to add the water features till later, then get the pump for those features at that time.