New pool question

[Jtravapd]

I don't re bee the demensions but it's in ground, about 35 feet long and 20 feet wide. Just estimates. Deep end is 12 feet. This summer a new liner was put in, concrete was dug up and all new lines were ran to all the outlets and skimmer. I have a Hayward earth de filter, with brand new filter/fingers insert inside, for weeks we couldn't get it to run correctly. After a backwash , filter pressure would go up to 30 in 30 min.

finally I checked the 1 1/2 multi port valve which was broken and cracked. Two questions .

1) all last year I was constantly vacuuming what looked like sand in the pool. Could that "sand" be the earth going back into the pool due to having a cracked and broken multi port valve?

2) even after changing everything , backwashinf, rinse, ect ( remember the filter insides are all brand new) pressure still would go up to 30.

then I tried something out ,right next to my skimmer is a small opening the size of a return jet which also feeds water into the filter like the skimmer does. I closed that valve and am just using the skimmer to. Pull water into the filter. Doing this the pressure is now steady at 10-15. Can just keep that other port closed?or at least restrict the water flow from that, or is it needed?

Thnan, you in advance for the help.

 

[pooldv]

Welcome to TFP!

That sounds like you were fighting an algae bloom the whole time. Those are classic symptoms of algae in the pool. Dead algae on the bottom and clogging up the filter quickly. Algae problems in the pool are caused by insufficient chlorine. This is often made worse by high CYA.

Give us some current test results.

Have a read here, Pool School - ABCs of Pool Water Chemistry

The way to kill algae once and for all is to follow this, Pool School - SLAM - Shock Level And Maintain