I'm always reading threads to find out if my problem might already be answered by someone else's problem. That's why I'm tailing onto this one. I've got foam on the surface of my pool and it looks like there are bubbles in the filter. I've never heard of opening the filter, but it sounds like that worked here - is it the hole at the top (I have a Jacuzzi - ST24). Does it open easily and should you keep the pump running?