Changing the water filter on our pump is a major undertaking, and probably the most frustrating thing to be done at The Rice Paddy. The lines on both sides of the filter must be turned off, and then the housing must be unscrewed, and the old filter removed.
Now the fun starts. You have to fit the filter down onto a sort of peg at the bottom, fill the housing with water, and then screw the thing together with the top of the filter fitting onto a little nub at the top. The water makes the filter float, and it skitters sideways every time you try to screw it all back together.
Many years ago a friend had told me that when her husband had to repair a leak in their baseboard heating system, he put a small plug of store-bought white bread into either end of the repair. The bread kept the water back long enough to solder the leak, and once the system was turned back on, the bread dissolved. So, we put bits of store-bought white bread around the filter to keep it from bouncing up, and it worked like a charm. We were both so pleased with our selves!
Until today, when we discovered a large blob of moldy green stuff bobbing like a boat in a storm, on top of the filter.
Yetch.
thisendoftheswamp 
Eew that would be gross, but good it worked at the time:)
I think the problem is that you only need a dab to plug a one-inch pipe, and we needed a LOT more bread to tie down that filter.
Ok that makes sense!