Low pressure on the pump

[matt4x4]

I would replace the pump seals before dropping 200 bucks+ on a new one unless there are other things that you know for sure are wrong.
I'm wondering if your inpeller stops spinning (slipping on shaft) when you put the vac to it and the resistence increases....
As for the sand - how long have you had your new filter running, supposedly, they do tend to push sand out until it all compacts nicely, I'd just vac it back in for a while see if it stops. Oops - forgot, you can't vacuum

[The Raddish]

The new filter has only been running for about three weeks.

It's alright. I've bought the Pentair Dynamo 2-speed mentioned in my OP. With as much else as has been wrong with this pool, I don't mind spending the money to do it right. Besides, it will pay for itself since it is only a 2.6 Amp draw on low speed, where it will spend most of its time. Even the high speed setting is only 8.6 Amps. Compared to my current 1hp pump which draws 12 Amps, it'll pay for itself by the end of the season anyway.

With this purchase, the only parts of this pool that came with the house are the metal wall and drain. Everything else has now been replaced.

Basically, I have a new pool.

[jenpen400]

I think you will be very happy with this pump. Don't forget the O-ring lube for the lid over the strainer basket.