Sand shooting thru return jet.

[Skiaeax]

I just bought a house with a pool last fall, and now I'm finishing up slamming the pool because it was green. Its been a week and the water is looking clear although it is still a little cloudy. I shut off my pump to rinse out the pump's skimmer basket and when I turned the pump back on, the jet shot out a brown cloud. I found out that it shoots out this brown cloud every time I shut the pump off and then turn it back on. I caught some of the brown cloud in a sock and found out that it is my filter sand.

Some background, last fall when I closed the pool I found out that the PVC pipe in the sand filter was broken and all of the sand was gone. I replaced the PVC pipe and put brand new sand in the filter.

Some ideas I have are: A bad lateral or I didn't install the new PVC pipe correctly. Is there any chance the multi-valve could be the problem? I'm debating between replacing the laterals or replacing the entire multi-valve assembly.

Any thoughts on what to do to fix this?

 

[RobbieH]

Bad lateral or laterals or other elements not fully connected, or broken manifold are the likely issues. I am pretty sure a bad valve won't do it.

 

[Skiaeax]

Sorry, but I'm new to pool ownership. What part is the manifold?

 

[Texas Splash]

In this pic you see the vertical standpipe that goes down to the manifold assembly where the laterals (fingers) are attached.

 

[Skiaeax]

I bought a new manifold and lateral assembly and replaced the old one. I think the probably was that I wasn't back washing and rinsing the filter when it got air in it. I found out that when I vacuumed the pump didn't stay completely full with water and some air got in it. When I pulled the vacuum off some of the dirty water in the filter got blown back into the pool while the pump got a blast of new water. If I turn the pump off before I pull the vacuum off, then backwash and rinse, no dirty water gets sent into the pool when I turn the pump back on.