i was wondering if someone can point me to the right direction here.
if i run my pump on filter for 2-3 hours, it gradually increases the pressure from 10psi to 20psi to the point that very little water goes into the pool. in looking into this some more, i noticed that my DE filter is indeed clean and the problem is that not too much water is coming into the pump.
If i stop the pump for a second, put the filter level on WASTE for 5 seconds (5 seconds is enough for water to flow back into the pump and i can see it from the skimmer basket on the pump), and then put the pump back on FILTER i get another 2-3 hours of good water flow.
My filter grids are sparkling clean (I cleaned them up this weekend, including acid washing), the pool is clear, and backwashing does not help this.
My only assumption is that something is leaking air into my pumping system, but i dont know where to start. as an aside, if i run the pump on RECIRCULATE, it will run all day at full pressure without any issues.