Leak from top of Sand Filter

[davidjpowell]

Hello - just joined as I am having problems in getting to grips with a problem we are having.

In ground pool, with a Sand Filter. I recently vacuumed the pool, and did a backwash and a rinse.

At that point water started to stream from the top edge of the clear lid. The lid itself is new, and is on it's 2nd seal, as that was my first try.

I can seal the lid fine, and generally as the pressure builds up, it holds. However as soon as the pool switched off, and then back on water will again come out.

Any ideas would be gratefully received.

Regards

David