mchldelf:
Here's a Pool School article on how you can go about determining the proper pump run time for your pool:
http://www.troublefreepool.com/pool-school/pump_run_time. This is the method I used to determine pump run time.
Since switching to BBB, I have been able to reduce my run time from a peak of 10-12 hours down to 5-6 hours using the same pump & filter. Even after you determine what works best for your pool, you may have to make adjustments for factors such as high bather loads, heavy rain (which washes debris out of the atmosphere), etc.
As for breaking the run time into multiple chunks vs. one continuous run, that's up to you. At a minimum, you want to aim for one complete turnover of water daily. The amount of time necessary to do this depends on your pool/pump/filter combination. For example, my run time would increase if I replaced my current 1-speed pump with a multi-speed pump and ran the new pump at a lower speed to save on electricity.
Now that we are approaching the peak of high water temperatures (for my pool based on logs I've kept over the last 2 years), I manually run my pump for about an hour or so in the early evening so I can run daily chlorine & pH tests while there is still some daylight and dose as needed. Pump will come back on around 1 AM and run for another 4.5 hours. By having a majority of my pump run time during the cooler temperatures of the wee morning hours, aeration from the waterfall spa into the pool will keep water temp down a few degrees from what it would be otherwise. Once we get to Labor Day, I will probably go back to one continuous run from late afternoon through mid-evening.
