WTF is wrong with my pool?

[stealth]

All I want is to clean and vacuum it so it can be winterized, when I ran into all this trouble. I've got sand in the bottom of it now (so I took apart the filter, took out the sand, checked the laterals, and put in brand new sand.

Now I have very weak pressure at the jets when the filter is set to filter (but shows excessively strong on the filter gauge). When set to recirculate, the filter gauge seems normal and the pressure at the jets seems strong.
When I go to backwash, it *seems* as if it shoots a blast of water and sand from the filter into the pump basket. Backwash and rinse pressure (at the outlet) seems very weak, although the gauge shows it excessively high (this was the initial reason I thought replacing the sand would help, but it hasnt).
The filter does seem ot make some noises (sometimes gurgling or hissing). The filter is only about 3-4 yrs old (Hayward).

Anyone?

[Drthorne]

did you go through the trouble shooting list?
http://www.haywardcanada.com/ingroun...ng/filters.cfm

[stealth]

Ya, not much there that I think would apply, since I've had the the filter for a few yrs, replaced the sand, and the laterals looked ok to me.