Filter pressure low

[CurtisT]

My filter pressure had gone from about 10 to 20 PSI so over the weekend, I cleaned the filter and gave it a bath in TSP. I reassembled it yesterday morning and the pressure was down to about 10 again. I closed down the valve to the wall returns about half way to direct more flow to the in floor cleaning system, bring the pressure up to around 15.

Today I check and the pressure is around 5PSI and there seems to be very little flow to the in floor cleaning system (heads only pop up about half way. I have no air in the pump basked so I know I'm getting good flow into the filter (just to be sure I've opened up both skimmers and the main drain all the way).

Any ideas what could be going on?

I'm not sure if it's related or not, but we had 2" of rain yesterday... every time we get 2+ inches, my pool turns kind of a murky green ( I think the big Oak hanging over the pool drops something or gunk washes in from the yard). The filter has been running all day and it's back to its normal color, just a bit cloudy still. I expect that it will be clear by the morning (24 hours straight running the pump always clears up the problem).

 

[JohnT]

Low pressure is usually a symptom of inadequate water flowing into the pump or a clogged or dirty impeller. If the strainer is full all the time, shut the pump off and pull the strainer basket and reach into the impeller housing to check for debris.

 

[Bama Rambler]

Seems like I'm constantly following JohnT. :|

My first thought when reading this was that the impeller was clogged. Be sure before reaching into the impeller are that the breaker is off and not just the timer.