Light green pool, looking for help

[jst154]

Got a 18x32 above ground pool last year with a SWG and sand filter. Decided not to drain it over winter, but my cover kept coming off and dumped a ton of leaves in the pool. I uncovered it a week ago and couldn't see the bottom it was so dark. Pulled probably 50+ leaf skimmers full of leaves out, been vacuuming and brushing (side walls were green and slimy film). It had no CYA and my SWG says 2800 ppm salt (3200 to end last year, but added 8" or so of new water due to frequent backwashes). After several days of this (and SLAMing to 10 FC per the instructions), I could finally see the bottom, vacuumed the remaining leaves and thought I'd be done in another day. Added some CYA to not lose any FC. I then ran other tests and found the below:

FC 19.0
CYA 60
CC 0
Ph 7.4
TA 110

The sides are no longer slimy, but there's still a pretty substantial green tint to the water. I ran a OCLT and it dropped from 19.0 to 17.0. After adding CYA and testing it as 60, I bumped up my FC to 24 (per SLAM) and it's been like that for 3 days, with no real improvement in the water clarity or green tint. I still vacuum and backwash the filter daily, but it's not really getting better. Ideas?

 

[IceShadow]

How often are you testing and bringing it back to 24ppm FC?

 

[IceShadow]

Also that photo makes the water look fairly clear. I can see the liner pattern through the green water. It might be worth having a pool store test for metals (but don’t buy their potions). Where is your fill water from, well or municipal water?

 

[jst154]

I've been testing and bringing it back 1x/day for the last several. Didn't add anything yesterday (been using 10% bleach), tested this morning:

FC 17.5
Cc 0
Ph 7.4
Ta 80
CH 150
CYA 30

It's well water. I definitely get brown soup when adding salt in the past due to iron content, but when I filled it last year (and added salt), I put an inline polyfill filter on and it cleared up the water in like 3 days, so I don't think it's that. I just leave the polyfill filter connected all the time now so I don't have to worry about it. And, 3 days ago I pulled out the polyfill and rinsed it out so it shouldn't be that.

It's definitely clear enough to see the bottom, but it's not clear blue like it was all of last year.

 

[jst154]

Here it is today, same green tint. I thought it might be the liner discolored, but notice the white vacuum hose gets darker the closer to the bottom, so it's definitely the water.

If I have the pool store test, what am I looking for?

 

[splashpad]

If I have the pool store test, what am I looking for?

Metals detected of any kind. It's not the levels, just whether they are there or not.

Have you put in new poly-ill? If you’ve got iron in your fill water, use Polyfill to remove it

 

[IceShadow]

I think it's very likely that the high chlorine levels are causing your iron to fall out of solution. See if the polyfill is catching anything now that it's greener.

 

[jst154]

Have you put in new poly-ill? If you’ve got iron in your fill water, use Polyfill to remove it

I didn't replace the polyfill, just took it out, rinsed it til water was coming out clear when squeezing it out, put it back in.

I think it's very likely that the high chlorine levels are causing your iron to fall out of solution. See if the polyfill is catching anything now that it's greener.

But if it's causing the iron to come out, wouldn't the polyfill be catching it? It seems like my pump/filter do a good job turning the water over, since last year when I had the iron problem it went from dark tea to crystal clear in 3 days....it was maybe this light after 2 days and the next day it was clear. It's been this tint for 4 days now.

Guess it wouldn't hurt to replace the polyfill. I just figure I would've noticed an issue last year since I had to add more well water in August due to lack of rain....not 8", but probably 5" and it didn't get a brown tint. Plus, I didn't clean the polyfill at all until a few days ago.

 

[splashpad]

I didn't replace the polyfill, just took it out, rinsed it til water was coming out clear when squeezing it out, put it back in.

But if it's causing the iron to come out, wouldn't the polyfill be catching it? It seems like my pump/filter do a good job turning the water over, since last year when I had the iron problem it went from dark tea to crystal clear in 3 days....it was maybe this light after 2 days and the next day it was clear. It's been this tint for 4 days now.

Guess it wouldn't hurt to replace the polyfill. I just figure I would've noticed an issue last year since I had to add more well water in August due to lack of rain....not 8", but probably 5" and it didn't get a brown tint. Plus, I didn't clean the polyfill at all until a few days ago.

There are several good threads on here about dealing with iron in pool & fill water
This one references what I was thinking: Polyfill use during AA treatment

I would rinse the polyfill daily (when you are seeing tint or color in the water) and replace it weekly, it's cheap enough that having crystal clear water would seem more desirable

 

[jst154]

Welp it's been raining so I haven't been able to do anything for a couple days. Went out this morning to change the polyfill and it's pretty well cleared up. FC is at 9.5, didn't check anything else.

Always makes me uneasy when problems fix themselves, means it could come back any time.

 

[IceShadow]

As FC lowers, the iron goes back into solution. Probably the difference here.