I'm going to throw this out there even though I suspect I know what the problem is. During the first couple days after opening I've had to backwash my DE filter 3 times. The pressure goes from 12psi to about 20psi in 1/2 a day and the water flow slows down.
Now, I think the problem is that its been a very mild spring that has lasted a month already. The water is darker with more algae than any year before. I think thats the issue.
So, should I keep on backwashing? Or should I bypass the DE filter, and once the chlorine kicks in will it oxidize the algae? I was low on salt so my SWG just kicked in later yesterday.