Pool Pump issues

[Impulsive57]

I had a pool pump replaced and the pool company put in a pump that is .5 Horse power less then my old.I am having a hard time getting good enough pressure when I use it through my filtration container but on recycle it is better but still not as strong as years before. Will that make a big difference on a 18' X 36' , 23.000 gallon rectangle DE pool?

[PoolDoc]

What do you mean, when you say

having a hard time getting good enough pressure

Are you not getting enough SUCTION, when you vacuum?