Pump weakens when vacuming

[britinusa]

Could you post a picture of the filter?
Is there a label on the side?
I have a DE filter.

[Coach]

Sorry I have been out of town, but while gone one of my friends told me they were having the same problem and changed their filter sand. I did figure out that mine was a sand filter by the way. So this morning I pulled out the old sand, about the last 6 inches of it on the bottom was as hard as concrete, had to break it up to get it out. I guess this was the problem as it works like a champ now. I'm not sure what caused it to do this in just one season but I was vacuuming to my filter alot. Thanks for the help maybe this thread will help someone else too.