Found this forum while researching a pool problem & the bbb method.

22,000 gallon IG gunite pool running a DE Hayward filter DE-4800 (48SQFT 96 GPM), Hayward Vari-flo multi-port valve 715XR60, Pump - Century Centurion 0-177215-04 1hp

My pool is a mess and we are trying to decide what to do next. We were having an algae problem with our chemistry getting all off when we noticed after a backwash that our pool was still leaking out the backwash line. We looked it up and found the most common problem was the spider gasket. Sure enough the gasket was warped and torn. We researched it and replaced it. I'm pretty sure we did it correctly, (glued it down with silicone sealant from leslies pool supplies, ridge side up) but in the process the screws that held the top of the mpv on became badly stripped (were already a little stripped). We also noticed that afterwards the handle was hard to switch between settings. After getting it back together we tested it and it still leaks, we also found that it leaks in recirculate setting. So we can't get the mpv open now and we cant run it without losing considerable amounts of water. Other than completely replacing the mpv I am at a loss as to what todo. In the meantime my pool has gone from kind gross to full on bad. I'm afraid we may end up needing to drain it completely. Suggestions?

Any ideas how to get the stripped screws off?
Does it still sound like a spider gasket or something else?
Can anyone direct me how to replace a mpv?

Our pool details are: 22,000 gallon ingound gunite pool running a DE Hayward filter and using a Hayward Vari-flo multi-port valve. What we plan to replace it with if it is needed is a Hayward SP0715XR50 Pro Series Vari-Flo Control Valve (newer model of the same valve we already have).