Should sand filter have goopy build-up on top?

[wes8398]

I gave it a good 5 minute backwash and 2 minute rinse today and then took the head off to inspect the sand. It appears that there is some type of sediment in the sand that's not backwashing out. It's really hard to describe (hence the pictures) but when I take some out it felt like wet paper or wet cotton balls ... Not sure if this is from a product I've used or what, but like I said, it doesn't backwash out. Any ideas?

 

[teapot]

Wes8398, by backwashing you have a least brough the gunk to the surface, some lage particles don't always backwash away as they won't fit through the rough grid on the bottom of the valve. Your pump maybe not quite powerful enough to shift it also as you dont say what size the filter is.

I would suggest you use a shop vac and get it out that way and top up your sand if required.