DE in the pool

[handyman]

Why is there DE covering the bottom of the pool? I have replaced all the filters in the tank with new ones. I have checked for leaks and proper fit but no matter what, all the DE goes back into the pool.

[Filter Helper]

Are you perhaps adding too much DE?

What happens when you vacuum the DE up? Does it go through the filter and end up in the pool again?

[handyman]

When I vacuum, no DE returns. My filter holds 6 pounds of DE. I put in 6 pounds after each time I clean the grids, but only 3 pounds after each backwash. (I'm told that only half of the DE is washed out with a backwash.) DE goes in the pool after the backwash. I've started putting in the DE with the spider valve on rinse...that seems to stop the DE from going into the pool, but I wonder if it is going out into the sewer before I move the spider valve back to filter.

[Filter Helper]

I wonder if it is going out into the sewer before I move the spider valve back to filter.

I think it probably is. Do you think the rate at which you add the DE has any influence? Would adding the DE slower change the amount of DE returning to the pool?

The fact that the DE sucked up by vacuuming the pool stays in the filter seems to indicate that the filter grids have the capacity to hold the amount of DE you are adding. Perhaps you could try adding less DE, say 2 pounds, and see what the result is. At the moment you are discharging a portion of it to waste anyway.

[handyman]

Thanks...I'll try that. I read somewhere about a "DE blush" that occurs after a backwash when DE is added to the skimmer. Maybe, that is what is happening.