Help with sand filter operation and algae

BobW0295

Active member
Sep 10, 2010
41
I have a similar problem with my sand filter.

I have been battling algea and cloudy water for a month. I tried every chemical the store can sell then I noticed that my filters pressure had not gone up even though it had been running 24 hours a day for a week without back washing. I changed the sand then noticed that when I tried to vacuum the algea off the bottom it went right through the filter. I changed the spider gasket (same as pictured above) but same problem. After replacing the spider gasket there there is a lot of play in the valve handle. I pushed the gasket in as much as I could and there is no leaking from the backwash port. I used silicone spray to make it easier to get the gasket in place. The valve sits on top of a pvc return tube from the bottom of the tank. My next step will be to replace the O ring that goes around the tube. After that I an considering replacing the whole valve or maybe going to another type of filter although its only 4 years old.

It is a Columbia Valve and tank. Anyone have any experience with this companys products?
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,036
SouthWest Alabama
Welcome to TFP.

Can you post a full set of test results?
It sounds like you still have live algae.

The spider gasket should be glued to the bottom section of the valve. If you used lube to install it, it may have slipped out of one or more if the dividers. If you take it apart to inspect it I'd go ahead and replace the stand pipe o-ring.

Once you've resolved your filter issue we'll attack the algea issue you have.
 

duraleigh

Admin
Mod Squad
TFP Expert
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LifeTime Supporter
In The Industry
Apr 1, 2007
31,691
Sebring, Florida
Hi, Bob,

As bama said, get your filter fixed (if it's broken) but do not think of your filter as the reason you have algae.

You have algae because your pool lacks chlorination.

So, once you get satisfied that the filter is functioning, you will need to post test results and then we'll go to work killing the algae and your filter will clear the pool.
 

BobW0295

Active member
Sep 10, 2010
41
I replaced the multi port valve and have the filter runing 24 hrs a day. I had super shocked it before deciding to take the filter apart. After sitting for 5 days the water was only sightly cloudy until I brushed the bottom and sides now its very cloudy but not green.

Tested water:
CYA 90
FC= 1
TC=1
TA = 120
PH =6.8

any suggestions?

24 x 52" round 1.5 hp 150lb sand filter
 

dmanb2b

TFP Expert
LifeTime Supporter
Apr 4, 2009
3,734
NY
Welcome to TFP.

Your PH is too low and you should raise it to 7.2 asap with Borax. Next, with CYA at 90 your FC shock level is 35. Until you raise your FC to 35 and hold it there until the pool clears, you will not be shocking.

If the CYA test result is accurate, you may want to consider a partial drain and fill to lower CYA. The higher your CYA, the higher the FC requirement to shock.

Read through Pool School...button on upper right of page, and feel free to ask questions.

Getting your own test kit can do wonders for taking charge of your pool.
 

BobW0295

Active member
Sep 10, 2010
41
Had the water tested today. the CYA is at 150. Draining and refilling now doesnt make sense sinse my swimmng season is over. At this point I think it may be better to cover the pool and start fresh next season.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,691
Sebring, Florida
At this point I think it may be better to cover the pool and start fresh next season.
I would do the same, Bob. You'll get some dilution from rainwater/snow over the winter and be able to adjust your CYA in the Spring and you'll be off to a great start.