Another newbie struggling with green/cloudy water

[joesparkie]

Long story short, I found this site a few weeks ago after fighting on-again, off-again green/cloudy pool water all summer long. I've read through the other threads that dealt with the same topic and thought I understood what needed to happen. I bought the Taylor K-2006 test kit with the Speed Stir, and have since had to order refills of the R-0870 and R-0871 off the TFTestkits website. I got my pH and CYA back in line and then started SLAM on September 22nd. Things were coming along great until about the 4th day. Since then my water has been stuck in a cloudy/slightly green state; I am having trouble seeing any further improvement. I started the SLAM process with the following values;

FC - 0
CC - 0
pH - 7.4
TA - 220
CH - 420
CYA - 60

I have only tested for FC the last 12 days, 2-3 times per day, at least before and after work, and usually right before bed. I am keeping FC at 24 ppm as shown on the Chlorine/ CYA chart. Any ideas on how I can get this cleared up? Here in my neck of the woods I'm running out of time before the weather starts to turn for the worse. I've attached a picture of the water. Thanks for the help.

 

[jblizzle]

Welcome to TFP!!!

Have you tried the Overnight Chlorine Loss Test?

Have you ever inspected your filter and deep cleaned the sand?

Looks like you could have all the algae killed and are just struggling with the filtration.

 

[joesparkie]

Thanks jblizzle. I have not tried the OCLT, I thought the pool should be clear before performing that. I will try that tonight.

I replaced the sand in the filter at the end of the last year when I had to replace the filter tank (don't ask lol). I did not deep clean the sand when I opened this spring because I hadn't yet found this site. Learning more and more on here each day Is that something I should perform now, even though it is the end of our season?

I've always suspected the pump motor was too large for my filter, and somehow it is pushing the finer particles through the sand instead of allowing them to be filtered out. It was a 'free' upgrade from the pool store. Does that sound reasonable to an experienced sand filter owner?

- - - Updated - - -

FYI, when I tested for FC this morning, I was right at 24 ppm, so the overnight showed no loss. However I did not perform the CC test. That has happened a few times the last few days, usually when the overnight temp is less than 55 degrees. I really wasn't paying too much attention because I thought I needed to have clear water to perform the OCLT.

 

[jblizzle]

Does not hurt to clean the sand yearly. But a pump that is too big could certainly push the debris through.

You could try adding a little DE to the filter and see if that helps.

 

[duraleigh]

Are you running the filter 24/7? Are you backwashing frequently? Does your psi rise daily?

You are partly right about no need for the OCLT until you are clear but we use the OCLT for two purposes....

To tell us the SLAM is complete by meeting these criteria (and, of course, you need clear water for this)

1. Your pool water is sparkling and there is no visible algae (dead or alive)
2. Your CC's are .5ppm or less
3. You can hold your FC overnight without losing more than 1ppm.

The second reason is to detect whether or not there are still living organics in the pool.

In your case, the water looks like all living organics have been killed but an OCLT will confirm that by verifying that FC loss is not more than 1 ppm.

 

[joesparkie]

I do run the filter 24/7. I have not backwashed since I started the SLAM because the PSI has not risen 20% from it's normal PSI.

I will perform the OCLT tonight and report back in the morning. I'm guessing that if the OCLT is successful I should start looking at the filter?

 

[duraleigh]

Yeah, if the psi isn't going up, you are not catching anything. That means that the filter is not filtering like it should.

Assuming you pass the OCLT (Lose 1 ppm or less overnight), I would break down that filter and look at the insides.

Your gauge is working, right? (psi goes to zero when you shut off the pump)

 

[joesparkie]

I passed the OCLT test, lost .8 FC and CC held steady at .4. I added 4 cups of DE last night, and overnight the PSI only raised .5. I guess this weekend I will tear the filter down and see what's going on. Should I continue to hold the FC at SLAM until I get the filter working properly?

 

[duraleigh]

You can let your FC drift down. You have killed the organics in your pool and now need good filtration. Let us know what you find.

 

[joesparkie]

I suspect it is the center riser pipe on the lateral assembly. We had to buy a new multiport valve last spring due to leaking, and the center riser didn't quite fit tight into the new multiport as it had in the old multiport. Pool store told us it would be fine (imagine that). From what I remember, that center riser was thin, like a c-pvc pipe. Any reason I shouldn't splice a new section onto the existing, rather than replace the entire center pipe? Should a standard plumbing pvc glue hold-up in the chlorine?