Dirty water coming back through jets

[Crumble]

This is my first post but I’ve lurked for a while, thanks to everyone here for helping keep my pool clear for the past 8 years. Everything was fine until this year.

I came back from a weeklong vacation to a pool full of green algae. Ok no problem, SLAM and vacuum it out. But after 10 minutes or so of vacuuming, I’m getting green algae water coming back out through the jets. Backwash and it goes back to clear. 10 minutes later it’s coming in green again. Eventually I got it all vacuumed out, but I can tell it’s not filtering properly. I’m thinking a crack in the laterals or vertical pipe, but I’d like to see if anyone has any ideas before I suck all the sand out and look.

 

[1poolman1]

This is my first post but I’ve lurked for a while, thanks to everyone here for helping keep my pool clear for the past 8 years. Everything was fine until this year.

I came back from a weeklong vacation to a pool full of green algae. Ok no problem, SLAM and vacuum it out. But after 10 minutes or so of vacuuming, I’m getting green algae water coming back out through the jets. Backwash and it goes back to clear. 10 minutes later it’s coming in green again. Eventually I got it all vacuumed out, but I can tell it’s not filtering properly. I’m thinking a crack in the laterals or vertical pipe, but I’d like to see if anyone has any ideas before I suck all the sand out and look.

Sand filters have a hard time filtering algae. It is best to add a handful of DE or cellulose fiber after each backwash as a filter aid until the water is clear.

 

[Melanie Kielty]

Are you rinsing after backwashing? I know you said you’ve been doing this for 8 years so not trying to belittle you.

 

[Crumble]

Sand filters have a hard time filtering algae. It is best to add a handful of DE or cellulose fiber after each backwash as a filter aid until the water is clear.

Thanks! I’ll give that a try. Do I take the multiport off the filter and sprinkle it on top?

 

[Crumble]

Are you rinsing after backwashing? I know you said you’ve been doing this for 8 years so not trying to belittle you.

Yep I always rinse after backwashing.

 

[inmytrunks]

Thanks! I’ll give that a try. Do I take the multiport off the filter and sprinkle it on top?

Hi Crumble, did this work for you? I'm having the same trouble as you described.

 

[Crumble]

The DE didn’t work for me. Before long it made its way through the filter and back into the pool… I could see the cloudiness coming through the jets.

I ended up sucking all the sand out of the filter and found that two of the laterals were sticking up at about a 45° angle instead of horizontal. When they’re up like this there is a hole on the underside that should be closed when they’re all the way down to horizontal.

I put them back down and put all the sand back in (it didn’t smell very good). It’s working better now but there is still some dead algae settled on the bottom a day after I vacuumed . I hope it’s just what I stirred up while vacuuming. I’ll vacuum it again today or tomorrow and see how it looks.