+ Pool volume: 12' x 30' x 5.5' avg depth x 7.48 gal/cft = 14,800 gallon => round down to 14,500, since you will not run the pool at overflow!
+ Whisperflo wfds-26 is has a 230V motor; I don't know what "115 olds" is, but I'm guessing you are saying something about the voltage.

If this is the case I should be able to just use one leg on one of the breakers and hook the other up to common right?
I'm going to be blunt . . . because when you mix electricity with pools in the wrong way, you KILL people. Your question tells me you SHOULD NOT DO THE WIRING YOURSELF! Period. End of story. You can watch and learn, but get someone who knows what they are doing!

Not sure where you are getting your prices, but a Pentair Intelliflo (vfd drive & motor on a 3HP Whisperflo front end) can be had for ~890 + shipping:
http://www.a1poolparts.com/-strse-34...tra/Detail.bok

From the same company, a 2-speed Whisperflo can be had for $570 to $740, but keep in mind you'll have to have a special time clock (DPDT) with the Whisperflo, but not with the Intelliflo.
http://www.a1poolparts.com/-strse-61...ump/Detail.bok


It's quite common for pool pumps from the better companies (like Pentair) to last 10 years . . . BUT make an effort to get your new pumps 2 - 4" ABOVE ground level. It will last longer if you do.