Filter/Pump Question

I have looked through a lot of the threads and have come to the conclusion that my issues with my pump and filter are caused by an air leak. The only leak I can find is on the multiposition valve. When the pressure gets high, I can see water dripping from the one end that is attached to the valve. I am going to replace the valve and the end fittings attached to it, hopefully that will solve my problem. The question I have is, in looking at the picture, can you see all the DE around the filter housing and pump? I have no idea on how this got there. I noticed it after I opened the pool this year. I have one last question, I have never been able to run my filter for more than 8 hours without having to "bump" it down. Even when condition were perfect, the pressure slowly rises and I have to bump it down. Any help would be greatly appreciated. I have a Maxflo, 1HP, pump and an EC50 Hayward DE filter, in ground, kidney shaped pool, 30X16.