Pump Pressure reading very low

[mphare]

I have a 4 yo 13,500 gal gunite pool with a Jandy DE filter system.

I backwashed my pool last weekend.

I noticed today that the pressure on the filter tank is reading very low less than 10 psi.

What might this be indicative of?

Thanks,

Mike

[ChuckD]

Certainly not to be a smart&ss, but what would you consider normal? What's your reference pressure? I have a Hayward EC65 with a one year old 3/4 hp Superpump. On a clean charge of DE it settles in at 11-12 psi.
Remember the pressure reading is of the water between the pump and the filter, or the force applied to push the water thru the DE/filter. If you feel your <10psi is out of whack it could be a weakening pump or not enough DE.

Has the pump run dry for any period of time?

[topless]

My profession is industrial pumps. Let me give you the basics.
First, pressure is resistance to flow. 1 of the 2 things listed has to apply.

If you are seeing the normal amount of water volume coming back into your pool, then there is nothing wrong with your pump. A lower pressure reading indicates that something changed between your pump and the pool. That something would be in your filter. For some reason you have less restriction.

If your water volume back to your pool is less, and less pressure, then you have a different problem and I don't have enough information from you to troubleshoot it. This type of pump would only lose volume suddenly if:
The intake line is restricted (then it will sound like it's pumping gravel).
If the pump impeller got some debris in it, which you would have to clean out.
It's not turning as fast due to an electrical problem. (this one is not my 1st choice).

[mphare]

Thanks. I consider about 10 psi normal, because that's what it's always read after a backwash for the past 3 years. There is also a 'Clean' indicator on the readout that points to 10 psi. But mainly it's the history that leads me to believe less than 10 is low.

I have a waterfall and a bubbler and as near as I can tell they are operating at a normal flow rate (the bubbler is fountaining about as high as it usually does).

I put in the requisite amount of DE after the backwash (6lbs) and the filter blades looked in good shape when I did the spring cleaning this year. But I suppose there could be a problem there.

There isn't any water around the pump area, everything is dry.

The pump did run dry once last season (from now on, I turn off the system when I go out of town).

Thanks again!