So, I've been fighting a swamp for the last week, which is a whole 'nother saga in itself. When I finally decide to take the top off the filter and hose off the sand I come to find the pipe going to the laterals is snapped guess that's why it wasn't filtering. It's an 18" Hayward.
It just so happens I have a larger 21" Sta-Rite filter not doing much of anything with perfectly intact laterals sitting in the shed.
So can I just hook up the bigger filter to the 1HP pump and be okay, or does it need a larger pump? Which incidentally, I also have. Although will probably be overkill for the current pool?