One Return line not working properly ?

[PoolGirlRose]

Hello- this is my second season with my inground pool 18 x 36 rectangle. It has 2 return lines, one with a red valve one with a black valve.

When I opened the pool and started vacuuming, the 2nd black return line started to almost immediately spit out dirty water. The other line appears to be normal clean water.

Ive been battling cloudy water for weeks now and have added a "flock" treatment which didnt work. I left it in the garage overwinter so I'm guessing it froze and wasnt effective. I bought a Super Clarifier from in the swim that has excellent reviews and after 1 day there is no change at all to the water. (last season I added the regular flock and had really clear water almost overnight and i could vacuum out the debris) The chlorine and ph levels are in normal/good range but water is cloudy with very very fine debris, thats why i added the clarifier.....

I started playing around with the return lines and noticed if I shut the red line off and have only the black line running return water there is nothing coming out but the filter seems to be holding pressure. (how can this be ??)

when I shut off the black line and have only the red return line open after a few hours the water is looking clearer already.

I'm sure last season both return lines were open all season. I ran my polaris on the black line (I thought) while the red line was open too. I have myself all confused now.

The skimmer is working fine and vacuum pressure is super good, so all that seems to be working ok.

I have a pool guy that helped me close and open it- but I cant reach him to ask. I found this forum and was hoping someone might have some suggestions ? Thanks for any help or ideas you might have. btw its a sand filter.

 

[Casey]

Welcome to TFP PGRose.

Please, stick around and read pool school. We encourage you to ask many questions as you find your way around TFP! You will find so many educational links to pool care and learn so much. Also, you should be using a reliable test kit so you can accurately read and dose your pool and know what it needs and when. We don't use FLOCK around here because it's never needed but maybe, (that's a very small .01% chance) 1 time it was mentioned to a user. Your pool just needs chlorine and filter time. You can check the test kits out here :lookhere: Test Kit Comparison. We highly recommend the TF100 as you will get more reagents for your money than with the K2006. Also, while you're here, read :lookhere: ABC's of Pool Water Chemistry



As far as your returns, I'll let someone else answer that.