Pool very green - chlorine not dropping overnight

[baudilus]

Hi All:

I very rarely post because I've never had a problem I couldn't figure out based on the amazing help here, but on this one I'm a bit baffled (or maybe I just need some encouragement to continue forging ahead). Went on vacation for a few weeks, and had a pool company come and service the pool while we were away; by the time they came for the first service, the pool was already very green, and they couldn't get a handle on it. (Not knocking the company, I think it went too long with no chlorine before the first came). Anyway, I've had a green pool before, and always resolved it with chlorine, brushing, and time using the SLAM process, which usually takes 1-2 days to go from green to cloudy, then another few days for the filter to clear it out.

Anyway, the part that's confusing me is that the chlorine is not dropping much overnight, but the pool remains very green (unable to see the bottom). I've attached a picture of the stairs, and here are the numbers (tested myself to confirm the numbers from the pool store) from this morning:

FC: 11 (started at 13 after sundown)
CC: 0
CYA: ~30
TA: 70
PH: currently testing at 8.0, but before I started slamming the PH was at 7.5
I tested phosphates too, they're around 400, but this isn't my issue.

The sand filter has very old sand, so that would affect how fast it's filtering, but even if I had the filter only on recirculate, wouldn't that just give me a super cloudy pool full of dead algae? I did add some DE and the pressure went from the base 23 to 31 within a few hours. I just booked an appointment to replace the sand tomorrow.

I have a feeling the answer will be stay the course, which I will; I suppose I'm just more confused why the pool is staying green and the chlorine doesn't seem to be doing anything.

 

[Bperry]

Hi All:

I very rarely post because I've never had a problem I couldn't figure out based on the amazing help here, but on this one I'm a bit baffled (or maybe I just need some encouragement to continue forging ahead). Went on vacation for a few weeks, and had a pool company come and service the pool while we were away; by the time they came for the first service, the pool was already very green, and they couldn't get a handle on it. (Not knocking the company, I think it went too long with no chlorine before the first came). Anyway, I've had a green pool before, and always resolved it with chlorine, brushing, and time using the SLAM process, which usually takes 1-2 days to go from green to cloudy, then another few days for the filter to clear it out.

Anyway, the part that's confusing me is that the chlorine is not dropping much overnight, but the pool remains very green (unable to see the bottom). I've attached a picture of the stairs, and here are the numbers (tested myself to confirm the numbers from the pool store) from this morning:

FC: 11 (started at 13 after sundown)
CC: 0
CYA: ~30
TA: 70
PH: currently testing at 8.0, but before I started slamming the PH was at 7.5
I tested phosphates too, they're around 400, but this isn't my issue.

The sand filter has very old sand, so that would affect how fast it's filtering, but even if I had the filter only on recirculate, wouldn't that just give me a super cloudy pool full of dead algae? I did add some DE and the pressure went from the base 23 to 31 within a few hours. I just booked an appointment to replace the sand tomorrow.

I have a feeling the answer will be stay the course, which I will; I suppose I'm just more confused why the pool is staying green and the chlorine doesn't seem to be doing anything.

View attachment 514816

You lost 2ppm chlorine overnight so it’s time to SLAM. Get your FC up to 28ppm and hold it there until you meet the three exit criteria.

 

[Newdude]

I've had a green pool before, and always resolved it with chlorine, brushing, and time using the SLAM process, which usually takes 1-2 days to go from green to cloudy, then another few days for the filter to clear it out.

It's exponentially harder when it's warm out.

How often are you testing/adding ?

The sand filter has very old sand

All sand is billions of years old. When was the last time it was deep cleaned ?

 

[baudilus]

You lost 2ppm chlorine overnight so it’s time to SLAM. Get your FC up to 28ppm and hold it there until you meet the three exit criteria.

Why 28ppm? Based on my CYA should be 12ppm.

 

[baudilus]

It's exponentially harder when it's warm out.

How often are you testing/adding ?

All sand is billions of years old. When was the last time it was deep cleaned ?

Testing every 2-3 hours. Keeping the FC at or around 12ppm. The sand was never deep cleaned; you think that's better than just replacing it?

And yeah, the water is unusually warm, so I figured that wasn't helping. And the rain here hasn't been helping either.

 

[Newdude]

Why 28ppm? Based on my CYA should be 12ppm

Correct. To @Bperry 's credit, I misread the 70 TA as CYA also. I think we're pre programmed at that # because SWGs

Testing every 2-3 hours. Keeping the FC at or around 12ppm

AWESOME. The more effort you put in, the quicker it goes, no matter how bad it might be.

The sand was never deep cleaned; you think that's better than just replacing it?

Yes. You'll know as soon as you get in there. If it's still sand like, even if it's filthy and gross, it will clean as good as new. If it's gummed up and/or rubbery, you need new sand.

Deep Cleaning a Sand Filter

This post will walk you through the anatomy of a sand filter, and then provide a video at the end for how to deep clean your sand filter. The filter used in the photos and videos is a Hayward S180T top mount sand filter. The images are of a similar filter. Obviously not all filters are...

www.troublefreepool.com

 

[baudilus]

Correct. To @Bperry 's credit, I misread the 70 TA as CYA also. I think we're pre programmed at that # because SWGs


AWESOME. The more effort you put in, the quicker it goes, no matter how bad it might be.

Yes. You'll know as soon as you get in there. If it's still sand like, even if it's filthy and gross, it will clean as good as new. If it's gummed up and/or rubbery, you need new sand.

Deep Cleaning a Sand Filter

This post will walk you through the anatomy of a sand filter, and then provide a video at the end for how to deep clean your sand filter. The filter used in the photos and videos is a Hayward S180T top mount sand filter. The images are of a similar filter. Obviously not all filters are...

www.troublefreepool.com

Thanks - will definitely check when they get here; I'm also going to have them add unions so I may just take the hit and replace the sand now, and then do the deep cleaning every year at opening. I could add the unions myself but I just don't have the time or inclination right now.

 

[Newdude]

so I may just take the hit and replace the sand now

If you're going to do *anything* you don't necessarily need to, this usually doesn't break the bank. Sometimes the effort/ aggravation isn't worth the savings.

 

[Bperry]

Correct. To @Bperry 's credit, I misread the 70 TA as CYA also. I think we're pre programmed at that # because SWGs


AWESOME. The more effort you put in, the quicker it goes, no matter how bad it might be.

Yes. You'll know as soon as you get in there. If it's still sand like, even if it's filthy and gross, it will clean as good as new. If it's gummed up and/or rubbery, you need new sand.

Deep Cleaning a Sand Filter

This post will walk you through the anatomy of a sand filter, and then provide a video at the end for how to deep clean your sand filter. The filter used in the photos and videos is a Hayward S180T top mount sand filter. The images are of a similar filter. Obviously not all filters are...

www.troublefreepool.com

Oops, yes would have sworn CYA was 70.

 

[Mdragger88]

keep at it
If your cya is below 30 you’ll be fighting with the sun too so perhaps make sure that’s a solid 30ppm