pool water around multi vale handle on filter

[rajung]

Just noticed something that may very well have been happening all the time on my 4 yr old sand filter.
Pool water is filling the cavity around the multi port handle and only seems to happen when timer turns pump off.
Never over flowing , stops and stays level with top by handle.
Next day when pump runs again by night time its dry again.
Pressure always around 16lb-I install a new gauge every year.
Just received all new o rings and flat disc washers other than the spider gasket in case I feel like replacing them but wonder if its something I should even worry about?
Thanks for any advice

 

[woodyp]

Any leak is a constant worry--no matter how small. Replace that spider while you're at it.