Loooooonng backwash drain - Problems?

[trbvm]

Almost done with the build..
I have a very long (150'+) 2 inch PVC pipe that is connected to the backwash on the DE filter. It goes all around the house and to the front - where I will be draining it to the sewer cleanout via a short 'blue' hose.

My PB mentioned that this long backwash pipe will actually cause me problems because there will be pressure 'loss' and backwash will not be that effective. He says that max of 10 to 15 feet of backwash pipe is most effective.

I am not sure how the length of the backwash pipe will affect backwash performance... thoughts?

 

[JamieP]

Is there an overall slope to it for gravity to help?

 

[jblizzle]

That is pretty long, the water will still travel that length. The flow rate will be a little lower than with a shorter run, but it should be fine. I wonder if you might get debris buildup in the pipe though.

 

[JamesW]

It should be fine for performance. I would suggest a vacuum breaker to allow the water to drain and to avoid water hammer when operating the multiport.

You should also make sure that the de won't cause an issue where you're draining it to.

 

[trbvm]

Is there an overall slope to it for gravity to help?

There is some slope - the drain is laid out along the longitudinal length of the house - whole yard is graded for drainage lengthwise.

- - - Updated - - -

That is pretty long, the water will still travel that length. The flow rate will be a little lower than with a shorter run, but it should be fine. I wonder if you might get debris buildup in the pipe though.

Yes, I thought about that.. but then I am hoping that if I backwash for a slightly longer time after seeing clear water, it should help in flushing the DE away and prevent blocking of the pipe.

- - - Updated - - -

It should be fine for performance. I would suggest a vacuum breaker to allow the water to drain and to avoid water hammer when operating the multiport.

You should also make sure that the de won't cause an issue where you're draining it to.

Thanks. We don't have a multiport valve. Just the push-twist-pull type (don't know the exact name of this type). I will turn off motor before operating this.
Where do you suggest I add a vacuum breaker? Currently, I just have the DE backwash port on the filter just connect to the long pipe. The other end opens to the front yard next to the sewer cleanout.

Prior to backwashing, I will be opening the clean out, attaching a small (3') blue hose to the end of the backwash pipe and just dangle the other end slightly into the sewer line - without putting it too much inside (yuck!)