Backflow / Waste Operation

[BigDave]

We're installing a new "real" AG (retired the donut) with sand filter. Will probably put some DE on sand filter for that "Sparkley Clean". Where should I discharge the Backwash / Waste? Do I run a line to the laundry sink?

[CarlD]

Up to you and your town. But from my own pool and experienc a backwash hose into a slop sink would overwhelm the plumbing rapidly. Think of a solid 1.5" column of water coming out RAPIDLY. I run mine into a storm drain. I recently put in a French Drain system for a soggy back yard and put in a Y-connection to run a 4" drain over to my pool. I run 1.5 inch TigerFlex into that drain for my backwash.

Carl

[AnnaK]

We're able to discharge directly into our backyard but we have a VERY big backyard, more than an acre. Friends of ours dug a very shallow trench, laid PVC pipe connected to an upright, and discharge into a low spot of their backyard via what looks like a splashy fountain. Another friend discharges backwash/waste down his driveway from where it runs into a sewer grate.

The laundry sink is probably not going to be able to handle it because its drain is smaller than the inflow hose.

[BigDave]

Thanks,
Yea, it didn't really make sense to me but the laundry sink is the largest access I have to sanitary sewer.

Would the DE and captured slop clog a french drain? Is there a way to catch the DE and big stuff that might stop it up?

[AnnaK]

The amount of DE that people sometimes add to their sand filters is minute and isn't enough to clog anything. The pressure with which water exits a backwash hose is impressive; we route it over a paver so it doesn't blast a hole in the lawn. As to big stuff, there won't be any big stuff in the filter medium. Big stuff is caught first by the skimmer basket and, if anything gets through, by the pump pot. At worst, you might get very small fragments of leaf bits or tree flower parts in your sand. What I see when I backwash is dirty water of a greyish brown color with tiny dark specks in it. Nothing to stop anything up.

[BigDave]

Thanks,
I'm a planner (too much sometimes) and I've been thinking my way through running the new pool. Plus I'm getting pretty excited even if it just a small AG.