Is my sand filter sized right?

[PoolDoc]

Carl, the Whisperflo is a more efficient pump than average, so a 1HP WhisperFlo moves more water than a 1HP SuperPump. Plus, the Whisperflo is often sold full-rate, so you are comparing a 1HP full rate Whisperflo with 1HP uprate (=3/4HP full rate) SuperPump.

The give-away that this is almost certainly the problem is early in the thread, when Goose comments that he's

almost certain than when I backwash I am losing sand, and I noticed that when I changed the sand that the level was a little low.

Flow is high enough to push dirt through sand BEFORE it gets high enough to blow sand out of the filter during backwash.

Goose, since budget isn't a big issue, I'd recommend the following changes:

1. Replace the TA60 with a TA100 filter. That will allow flows up to 70 GPM without overloading your filter. However, better clarity and longer filter runs will come with LOWER flows.
2. Replace your motor with a 2 speed 1HP motor . . . and run on low almost all the time.

If you want a timer, Intermatic has one that will switch speeds. But, using a toggle switch may be all you need. With a 1HP Whisperflo and a TA100 you'll be running 20 - 30 GPM on low speed! You'll probably need high only to backwash and vacuum.

Alternatively, if you want optimize things to the max, you can go with a Pentair Intelliflo, which is a 2HP Whisperflo with special motor and variable speed drive. I believe it comes with a built-in timer.

HOWEVER, please send photos of your piping at the the pump and filter before you start, and let me or Mark (mas985) look at it before you do. There are a number of piping practices that many pool builders follow that are HORRENDOUSLY bad, hydraulically. Correcting these can greatly improve your efficiency.

Here are links:
2 speed motor (A1 Pool Parts)
WhisperFlo pump
Intelliflo (Whisperflo w/ VFD)
Tagelus filters