I just backwashed and opened the top of my Pentair 4048 filter to thoroughly clean the filters. I put it all back together as usual and added the DE. But now I notice a small drop by drop leak under the filter right at the middle of the backwash handle. I opened the valve again to drain and re-fill and then started it up again and there is still a leak. I called the person who built the pool and he said sometimes the DE will fill in a small leak like that and that over time leaks like this can happen, but if it doesn't work I would need to call a repair person. I really like to try and fix things if possible by myself ( and save the money!) Does anyone have experience with this problem that might give me some advice? Thanks!