Backwash water no longer green - pure white

[Schmendrick]

I'm a DIY pool repair guy -- but only on my personal pool. I have an in-ground gunite pool with a DE filter. Having some issues, so thought I'd ask the knowledgebase!

I recently took the cover off my pool (dark green), so I cleaned the filter first, then added DE to the skimmers and added algaecide and shock to the water, then fired it up. I backwashed about every 6-8 hours, and the first few times, the backwash water ran clear/dark green/clear -- as usual.

But then yesterday, I backwashed again after 12 hours, and the backwash water ran clear/bright white/clear. That concerned me a bit, but recharged the filter with DE again. Then I started seeing DE shoot out of my jets. I immediately suspected a hole somewhere in my filter, so I took it out and inspected it. No holes ANYWHERE.

So, I assumed I hadn't seated it correctly the first time, so I positioned the filter very carefully back in the tank and made sure the connection pipe was tight. I let it run for another 8 hours and backwashed again. And once again: clear/bright white/clear. And upon recharging the filter again, once again, DE shot from my jets.

What am I doing wrong? I'm certain my filter is without holes. What should my next step be??

Thanks!
-Clint

EDIT by Moderator: I combined both of your posts that were waiting in the moderation queue.

[PoolDoc]

. . . membership upgraded.

White backwash from a DE filter, filtering water on a green pool, indicates the pool water is bypassing the filter.

What pump / filter / valve do you have? If it's a multiport valve, have you opened the valve to make sure the spider gasket hasn't blown out?