Clear water, with a green tint?

[sniklas]

Hey y’all,
At a bit of a loss. I’ve been SLAMing for 12 days, and the water has gone from a sludgy gray to clear (can see specs of dirt & debris at deepest end clearly, pics pre-vacuuming attached) but green. I’ve passed OCLT every day for four days and have kept FC at the appropriate SLAM level. When the water cleared to the point I could see every step, I replaced the filter. I have a heater that’s been running automatically as needed since I opened the pool, it’s < 2 years old. Yellow staining is occurring at the waterline, on the steps, and other underwater surfaces of the pool (waterline easily brushes off, haven’t tried with the underwater staining).

Current results:
FC: 16
CC: 0.5
pH: not measured due to SLAM
TA: 100
CH: 275
CYA: 40

Thoughts on the continued green hue and recommended next steps? Trying to ascertain if it’s necessary to keep water at SLAM given four consecutive days of passing OCLTs.

 

[mknauss]

Possibly iron or copper.
What type of filter do you have?

 

[sniklas]

Cartridge filter, Pentair EC-160318 clean & clear 200 sqft

 

[mknauss]

Open up the filter and see if the cartridge is turquoise.

 

[sniklas]

Open up the filter and see if the cartridge is turquoise.

Ok, I’ll check it out tomorrow!

 

[sniklas]

Open up the filter and see if the cartridge is turquoise.

Filter is not turquoise

 

[mknauss]

Great. So you likely have plain ol' algae to still kill.
Follow the SLAM Process

 

[Pool_Medic]

Green and cloudy is algae, green and clear is metals that came out of suspension.

 

[sniklas]

Green and cloudy is algae, green and clear is metals that came out of suspension.

Is AA treatment the recommended solution for metals in the water? Or just staining?

I think the odds are high that the entire interior of the pool is stained from metal causing the perceived discoloration of the water. I’m still maintaining SLAM levels for now…

 

[borjis]

AA treatment lifts the stains, then use something like Jack's magic pink stuff as a sequestrant to keep the metal in solution.

I did an AA 2 years ago and i couldn't believe how much more blue my liner turned back to after the staining was gone.

I have trace iron in my city water.

 

[sniklas]

*UPDATE*

The tint is clearly metal-based, not algae-based. Everything is within tolerance, with the exception of high FC and low CYA, both due to SLAM:

FC: 13
CC: 0.5
pH: 7.2
TA: 90
CH: 250
CYA: 30

Yesterday, FC didn't budge all day at 19.5, and this morning was still 19.5. Fast-forward, cover off the pool all day and FC down to 13.

My daughter and her friend are both blondes. My daughter’s hair is now tinted light green, but her friend’s hair is not. Fingernails are also not discolored. Yellow/brown staining exists almost everywhere - sides, steps, swim ledge, bottom - particularly worse in the shallow end but also present in the deep end.

I was positive this was iron, until the green hair, but it’s still odd that my daughter’s blonde hair turned green while her friend’s blonde hair did not…her friend lives next door, and we use the same (neighborhood shared well) water source for showers, etc.

I’m debating and somewhat confused on my next steps here. Metal stains happened the first and second seasons, though there were just a few. This season, it’s everywhere. It’s an in-ground pool, so the same water has existed (minus top offs) since 2022. I have a Pentair MasterTemp 400 heater, for which the heating core is copper, but used it for a bit the first season and all of the second season with balanced water and no problems, so I can’t believe it would be corrosion…

I put powder AA in a sock and wiped it across the stains and they instantly “lifted” onto the sock, so this is inorganic staining. I understand the process for AA stain treatments of the entire pool, but I’m super hesitant to constantly use a sequestering agent, especially if there’s copper. Water exchange sounds like a crazy-involved process, and the water rates here are exorbitantly high.

Any advice on:
1. The potential type of metal staining? Could it be both iron and copper?
2. Those who have removed metal staining, what was your preferred solution and why did you choose that solution?

 

[duraleigh]

The green staining is most likely from iron, not copper.

Copper typically stains the pool surface dark dark blue or turquoise. (or turn blond hair green)

Most all green colored pool water is from iron, however

Looks like you fill from a well........do you have a water softener?

 

[sniklas]

The stains are yellowish-brown. The water hue currently skews green. My daughter’s blonde hair IS light green after swimming, but her friend’s blonde hair is NOT green.

I have a softener, but I’m 99% sure it bypasses outdoor spigots.

 

[duraleigh]

Keeping two threads open about the same subject is really confusing.........I'll stay in this one.

The solution to your issue is to hook up a spigot so you can refill the pool with iron free water. It may take a while for that to happen but it should get rid of the copper, too, if it's in there. Next step for me would be to test for both so I knew how MUCH I had of each.

 

[sniklas]

Keeping two threads open about the same subject is really confusing.........I'll stay in this one.

Yes, I should’ve deleted the post on this thread once I posted to the other since the issue is metal and not algae.

The solution to your issue is to hook up a spigot so you can refill the pool with iron free water. It may take a while for that to happen but it should get rid of the copper, too, if it's in there. Next step for me would be to test for both so I knew how MUCH I had of each.

Thanks, I will do that.