Water cloudy after week of running

[chrisexv6]

Opened my pool last Friday, vacuumed to waste twice to get rid of the big stuff (mesh safety cover + opening mid-May = recipe for pea soup)

Fired up the filter in filter mode Friday evening, kept FC at shock levels until Monday (and FC is in fact still high)

Current chem test (22K vinyl IG, using BBB method):

FC - 5
TC - 5
pH - 7.4
CH - 90
Alk - 90
CYA - 0 (Ive added some, guessing it hasnt "shown up" just yet)

So basically the chemistry looks good. Even with 0 CYA the FC is holding (its been cool and cloudy ever since I opened the pool, go figure), plus I added some so it might just not be reading yet.

Here we are a week later and the water is still cloudy. I can see the bottom, but not like Im used to. Ive had the water clear enough that you could read the writing on our (now gone) main drain cover. We had the liner replaced last year and along with it the main drain was removed because it was leaking. The installers added another suction line in the deep end located in the wall (so yes, maybe we dont get as much circulation in the deep end now? but i had no trouble keeping crystal clear water all the way to the bottom last year)

Pool store (oh the humanity!) recommendation is to replace the sand, since everything else seems OK. The sand has been in use since 2003 when we opened the pool.

Im wondering what else I might look at? To me it doesnt seem like a chemistry issue. I wouldnt know what else to try OTHER than at least taking a look at the sand (maybe its channelled, but I figured Id see other symptoms of that). Only notable thing in regards to the filter is that I seem to have "lost" a couple PSI, running clean at 9-10, usually runs clean at 12 or so. No air in the lines, not losing water, etc. No leaks around the filter or pump.

Any ideas would be appreciated.

-Chris

 

[Richard320]

Have you passed the Overnight Loss Test?

Once you are sure the cloudiness can't be chemistry, that leaves filtration. I'd say a backwash, then a good stir to be sure the sand hasn't channeled would be the next step.

 

[Bama Rambler]

You using a recommended test to get those numbers? I only ask because it seems funny that both the TA and CH would be 90.

There are reasons to change the sand but not because it's worn out. It's a few million years old when you get it, so a few years in a filter isn't going to wear it out.

Since your filter is running at a lower pressure you could have channeling. If you've given it a good long backwash, I'd open it up, inspect it and clean it good with a water hose. Be very careful of the laterals when doing it and you'll be fine.

 

[dmanb2b]

Hey Chris...take a look to see if the sand is channeled. That 244 although adequate, will take a while to clear up cloudiness. 7-10 days easy, but what is important is that even though a sand filter can be slow, you should see clarity improving on a daily basis. If not, it's likely a filtration issue :<(

 

[chrisexv6]

Responding to all the replies (thanks for the quickness BTW!)

Havent tried to overnight loss test yet. I will do that this weekend, but since I was testing the darn thing every 4-8 hours I figured I would have known right away if something was still alive in there.

Yes its a recommended test (TF test kit, actually). I ran out of reagent for the CH test so I had the pool store test it. They were using a drop count test and I watched them, so I know it was at least fairly accurate (they were also Taylor reagents so I think it was the exact same CH test as the TF kit). All other tests were results from my testing, and actually matched the pool stores testing as well.

Sand has been backwashed twice.....once upon startup and once after vacuuming brought the pressure up to about 20. I plan on opening it up to check for channelling this weekend. The first day or so there was a marked difference in clarity (or at least color). Went from pea soup to aqua blue literally overnight, but since then its been a long slow road. Im not noticing very much clarity difference from day to day. I wasnt sure if channelling would cause a drop or a gain in pressure, but Ill check anyway. As far as I can see there is no sand getting back into the pool so Im guessing the laterals are OK. I suppose its possible the multiport might have an issue (water short circuiting filter mode and going thru recirculate instead?) I will take a look at the spider gasket when the valve is off to check the sand.

Thanks for the replies so far.

 

[Mesamav]

When I took the cover in March, my pool was green so I brought up the chlorine for a few days and it cleared up but was slightly cloudy for a couple weeks. I read on here to add a small amount of DE (or equivalent) to coat the sand in the filter and within 2 days, the water was sparkling. It brings up your pump pressure just a little but it sure clears up your water quickly.
Gotta love the guys here with all their cool tips. They are lifesavers.

 

[chrisexv6]

Just an FYI - I opened up the filter today, swished the sand around a bunch, it didnt seem channelled, I didnt feel any clumps.

Just for the heck of it I checked the filter manual to find out the correct sand level, and I couldnt believe how far off ours was.....2.5 bags (125 lbs) later, its at the level recommended by Hayward.

Where all of the other sand went, I have no idea. We've never had instances of sand in the pool that I could ever tell. No leaks from the equipment, valves, etc. When the pool was fixed way back in 03, we had the liner installer/builder setup the filter. I gave him the 6 50lb bags Hayward recommends, and I went to work. For all I know its never been right, but its definitely right now (and I will be keeping my eyes open for sand in the pool. i figured a broken lateral would have pushed enough sand into it that it would be obvious)

 

[poollover2012]

I just posted about my experience with adding DE to my sand filter, as I was also experiencing cloudy water for some time. My filter was doing the job but slowly so I thought I would give it a try. Wow! DE is working great so far after only a few hours.

 

[chrisexv6]

I just posted about my experience with adding DE to my sand filter, as I was also experiencing cloudy water for some time. My filter was doing the job but slowly so I thought I would give it a try. Wow! DE is working great so far after only a few hours.

Yep, Ive used that trick before. I like to wait until everything is up and running first, like in this case adding DE would have masked the larger issue of missing/possibly channeled sand.

Ill be buying a small bag of DE tomorrow, I might be seeing things but after a few hours of filtering with the missing sand the water looks at least a little bit clearer.