Backwash Issue?

[mllr]

Hey guys I am new here and new to the pool world. We bought a house in the winter that had a pool and it was well taken care off. Since November I had let the pool go a little and it turned green during the coldest parts of our winter which isn't cold (Louisiana). Lol Anyway I have pool back to blue water and almost clear. It was actually clear yesterday but I decided to backwash since I figured the filter would be dirty after having filtered a green pool. Once I put the pump on backwash I noticed that the dirty water was coming back into the pool through a port in the deep end that is just above the water line. So I immediately shut the pump off and switched it back to filter. I also noticed after a significant amount of rain that the sump pump also pumped the water to that same port and back into the pool.

Is there something wrong with the routing of my lines or is this normal? Do I just need to rig up a hose on that port and run it to my yard whenever backwashing so that it doesn't come back to the pool or do I need to demo the piping that goes from the filter on backwash and just put a hose there for backwashing? Any advice that you can give is much appreciated. Also in the pictures attached you will see the old sanitizer. I plan on converting to salt water next season so I will be doing what ever upgrades are needed to the pump area. I have already pulled the pump apart and replaced gaskets and o-rings due to some leaking that was noticed. Again, any advice is much appreciated.

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[JasonLion]

Welcome to TFP!

That is certainly not normal. It sounds very much like the pipes were routed incorrectly.

It is a fairly simple thing to cut the backwash pipe somewhere after it comes out of the multi-port valve and attach a flexible hose to the remaining part of the pipe. Just make very sure you are cutting the correct pipe.

 

[Richard320]

I'm just guessing, but I suspect your overflow and your backwash and sump pump are all teed together somewhere and the outlet is restricted, so it all ends up flowing backwards into the pool.

If you can't figure it out and fix it, then you will need to cut the backwash pipe and attach a hose to it. But if you do that, when the sump pump kicks on, it's going to squirt out the sawed-off stub as well as into the pool.

 

[JasonLion]

If Richard320 is correct, it could be fixed with a check valve or two.