Issue with Sand Filter

[HANKAVL]

Hello everyone, I just bought a home with a pool and in the last 2 weeks have been trying to get it opened. Read a ton on this site and thought i had it figured out. My pool had been uncovered for the last year and was a green swamp. I started the SLAM process and everything quickly died. The pool is a nice blue color but it instantly got cloudy and has not cleared up at all in 12 days, not even a hint of progress. You can not see below around 3 inches. All my test results are in order, will post them later when I am not at work.

I have come to the conclusion that my filter is having issues since I SLAMMED properly and for over a week and have 0 CC in my pool. It is a tagelus TA-50D, I do not know how old the sand is in the filter but I changed the broken multi port valve that was on it and when I looked inside it seemed to still have a good amount of sand. Based on some things I had read I decided to add DE to it in case the cloudiness was due to dead algae the filter could not pick up. The weird part is I only add a 1/4 cup of DE powder and it makes my pump rise 1 PSI super fast, then over the next few hours my PSI jumps from 12 to 19, which I had never seen it get so high before, but when I backwash the water does not even appear too dirty. Other backwash's before did contain dirty water though, but for the week before I tried DE and even with my pool looking like a cloudy mess the PSI would maybe go up 1 PSI every 24 hours it ran. So I am at a loss, since i poured DE in the skimmer and it did not seem to come out the returns and it raised the PSI of my filter I can assume that the laterals and other tubes in the filter are not damaged right? Should I try replacing the sand? Is there anything I'm missing? Also there is a small crack in the filter housing where it meets the flange at the top, it must be super small because it only dribbles water out of the filter periodically, could this cause drastic filter efficiency loss?

Thanks in advance for any help everyone can provide.

 

[cowboycasey]

Welcome to TFP, you will need to do a deep clean on your sand filter, it has probably never been done and the sand is "channeled" when you added DE is filled the channels and your filter started working better but it still is not able to backwash and clean your filter.. it may take awhile and use a lot of water but it will start to run clean... No need to change the sand out, it has been that way for thousands of years

Here is how to do a deep clean Deep Cleaning a Sand Filter

 

[tim5055]

While you very well may be having issues with your filter, have you followed the directions on SLAMing your pool in the How To section of Pool School and follow that procedure completely to the end.

* CC is 0.5 or lower;
* You pass an OCLT (ie overnight FC loss test shows a loss of 1.0 ppm or less);
* The water is clear.

It is only when all three are true that you are done SLAMing and can allow the FC to drift down to normal levels.

Have you passed the Overnight FC Loss Test (OCLT) yet?

 

[Charlie_R]

Have you tried deep cleaning your sand filter? It could be that it has channeled and/or has a lot of gunk in it that prevents a thorough backwash. In either case, the DE would still do as expected, and raise your pressure.

Sand really doesn't need to be replaced. As long as you do a deep clean once in a great while, you should be good.

My own experience:
I bought a used sand filter. The seller included the sand -- still in the filter -- and told me that the pool store they used told them to replace the sand every two years. All I did before I plumbed it into the system was deep clean, and add a small amount of sand to bring it up to the proper level. You wouldn't believe what crud came out of a supposedly clean filter! I repeated the deep clean after running it for a month, and got even morecrud out.

 

[HANKAVL]

Yes I have followed the directions of slamming and have got past the first 2 criteria to know when your done, yet getting the water to clear has become troublesome. It's been 12 days and there is just no change in the clarity of the water at all. Thanks for the tip to deep clean the filter I think I will give that a try. Seems like no one suspects any damage to the inner workings of the filter because I'm holding PSI so that is encouraging. Thanks for the advice guys!