Sand Filter & DE - backwash to yard

[vchavez]

I have a sand filter and I am considering adding DE to it to help it clean a bit better.

But, I backwash into my lawn currently, once about every 3-4 weeks. I understand the DE will be backwashed out, and I need to add it back in.

Is DE going to harm my grass? Is DE dangerous for kids or pets?

Thanks.

[CarlD]

DE will kill things like ants and other bugs. I don't know if it will hurt your grass, but the chlorine in the water probably will kill it.

I don't know if it's dangerous that way to kids and animals, but you aren't supposed to breath the stuff, so it may well be. Do you not have a storm drain you can flush it to?

[Poconos]

Breathing the dust is indeed dangerous but when you consider the small amount you add to a sand filter, then how this is dispersed onto the lawn, my gut says there is nothing to worry about. You would have to be in a severe drought with the lawn surface totally dry for any dust to kick up. It will also quickly work its way into the soil and become harmless. If you had a DE filter you would be dumping a load of the stuff and then I would think before dumping onto a lawn. As for chlorine killing grass, I doubt it. The sun will break it down quickly and also consider that some municipal water supplies have somewhat high chlorine levels, not as high as a typical pool, and watering the lawn doesn't kill grass.
I suspect one of the problems with dumping quantities of DE into a body of water with fish would be the DE getting into the gills and doing harm. Probably illegal too. But then again, dilution is the key. What Carl said about killing bugs is true. The stuff is small and sharp and cuts bugs bodies.
Al

[vchavez]

Thanks... I may give it a shot and see how it works. When the pool was built, it had a cartridge filter (yuk) and I converted it to sand, and I didn't pipe it directly into the waste plumbing, just figured it was water, and it would work to water the lawn too. (Live in AZ)

The waste plumbing line is at the front of the house, on the opposite side of the driveway.

Actually, the grass is greener where the backwash water goes... so the chlorine levels in the water are fine.. been doing this for 4 years now.

I may try the DE.. just in the summer since that is the time the pool gets used and is toughest to keep clear (water temps 85 - 92)

[Hszwill]

I backwash DE water regularly and it has never affected my grass.

Hope this helps,
Shannon in VA