Is this mustard algae?

[mcleod]

opened pool up w little problem this year. Slight SLAM. Passed the tests. Had clear H2O for 12 days then this shows up. Coincided w testing SWG percentages & pump run times. The bloom exploded in a few hours. Have data in PM app. Don’t recall if sand filter was backwashed after slam.

 

[JamesW]

The brown staining on the white fiberglass steps suggests that it might be iron.

The yellow might be mustard algae or it might be iron and some regular algae.

 

[duraleigh]

It is NOT mustard algae.

Did you chlorinate just before this showed up? Do you fill from a well?

Can you please post current test results from your own kit?

To me, it looks like iron has precipitated out of your water..

 

[mcleod]

The brown staining on the white fiberglass steps suggests that it might be iron.

The yellow might be mustard algae or it might be iron and some regular algae.

I’ve had had minor iron stains before, last year. Ignored them. Did an AA treatment when opening this year w/o adding sequestration chem. Could iron manifest in such a short time, in 24-36hrs? If algae, wouldn’t I be seeing lower FC (more than 1-2 points; I’m not at the moment)?

 

[JamesW]

Put a vitamin C tablet on the steps to see if it makes a white spot.

Iron can precipitate in minutes.

 

[mcleod]

It is NOT mustard algae.

Did you chlorinate just before this showed up? Do you fill from a well?

Can you please post current test results from your own kit?

To me, it looks like iron has precipitated out of your water..

I have rubbed the steps with Vit C and yes, there is an impact.
Well water? I belong to a co-op water system in E TX. Could be well sourced; not my well on my prop.
I have been maintaining chlorination since opening the pool in April. My target FC is 6.
I began the slamming protocol again yesterday afternoon. Pool Math recommends slamming with an FC 20. Latest numbers...
FC 18
OC 0
pH 7.4
TA 80
CYA 45
Temp 71

 

[JamesW]

It's probably iron, but the cloudiness indicates additional problems.

Metals are typically clear.

 

[mcleod]

It's probably iron, but the cloudiness indicates additional problems.

Metals are typically clear.

I have rubbed the steps with Vit C and yes, there is an impact.
Well water? I belong to a co-op water system in E TX. Could be well sourced; not my well on my prop.
I have been maintaining chlorination since opening the pool in April. My target FC is 6.
I began the slamming protocol again yesterday afternoon. Pool Math recommends slamming with an FC 20. Latest numbers...
FC 18
OC 0
pH 7.4
TA 80
CYA 45
Temp 71

@duraleigh @JamesW
Let me restate my assumption, as I think I wasn't clear on the previous threads. I think I'm having an iron issue, and possibly an algae issue.
1. (1st picture) Opened the pool 4/15. It needed a Slam.Slam done as proscribed by Pool Math App.
2. (2nd picture) Established (and met) the conditions for ending the SLAM, or so I believed. Clear water from 4/20 to 5/4. did a treatment of AA but no sequestering agent.
3. (3rd picture) Algae returned and/or iron intrusion?
4. Started a second slam yesterday, monitoring every 2 hours. Fluctuation between target FC and measured FC is about 2-3 points. Seems kind of a small variation for what "looks" like a serious algae problem.
5. Questions: Is the lack of sequestration of iron at first slam part of the problem? Can I address the possible iron issue while addressing the algae issue. Latest
FC 18
OC 0
pH 7.4
TA 80
CYA 45
Temp 71

 

[JamesW]

It looks like you have a lot of iron and it is almost impossible to keep it from oxidizing.

Iron Fill Water Filter - Further Reading

www.troublefreepool.com

 

[Dirk]

It looks like you have a lot of iron and it is almost impossible to keep it from oxidizing.

Iron Fill Water Filter - Further Reading

www.troublefreepool.com

Is it the chlorine that is oxidizing the iron, and turning the water yellow? And would a SLAM level of FC exacerbate that?

 

[mcleod]

It looks like you have a lot of iron and it is almost impossible to keep it from oxidizing.

But the water was clear for almost two weeks. Would not iron precipitate is less time than that?

 

[JamesW]

Is it the chlorine that is oxidizing the iron, and turning the water yellow?

Yes.

And would a SLAM level of FC exacerbate that?

Yes.

But the water was clear for almost two weeks. Would not iron precipitate is less time than that?

Not necessarily.

Iron can go for weeks or months without precipitating and it can precipitate in minutes under the correct conditions.

 

[mcleod]

5. Questions: Is the lack of sequestration of iron at first slam part of the problem? Can I address the possible iron issue while addressing the algae issue. Latest

@JamesW
5. Questions: Can I address the possible iron issue while addressing the algae issue.

 

[JamesW]

I would deal with the algae first and then deal with the iron.

Iron is tricky and difficult to remove without precipitating.

You can do AA to clear it, but the iron can drop out very easily.

Iron rusts, that's just what it does.

The iron is wet and there are oxidizers like oxygen and chlorine in the water constantly attacking the iron trying to get it to rust.

 

[mcleod]

I would deal with the algae first and then deal with the iron.

Iron is tricky and difficult to remove without precipitating.

You can do AA to clear it, but the iron can drop out very easily.

Iron rusts, that's just what it does.

The iron is wet and there are oxidizers like oxygen and chlorine in the water constantly attacking the iron trying to get it to rust.

Is Iron Out appropriate for this issue?

 

[duraleigh]

Is Iron Out appropriate for this issue?

No. It doesn't remove the iron simply returns it to soluble form FOR A WHILE.

I would suggest you positively identify the iron before you do anything else. Crush up some cheap vitamin C tablets in a sock (10 or so) and place the sock directly on the stains. It should remove the stains quickly if it's iron.

Tonight, perform an OCLT test to see if you lose chlorine at night. That will tell us if you have any algae. I think you will pass that test so now you can rule out algae and perform an AA treatment to get rid of the Iron.

How old are the test results?

Do you fill from a well?

 

[mcleod]

The numbers were collected @ 12:13pm. It’s 7:22pm here & will take a full spectrum test around 8pm. Will compare w tomorrow’s test & will report both tomorrow. Thanks one and all

 

[JoyfulNoise]

You also need to understand that an AA treatment effectively reduces the free chlorine to zero and will continue to keep the FC too low until you’ve oxidized the ascorbic acid with enough chlorine. This is why you don’t want to do stain removal treatment late in the season or during the swim season - once the AA goes in, the FC drops to zero and algae can start growing within hours. It always best to address iron staining either super early in the spring time when the water is still too cold for algae growth or at the end of the season when no one is swimming anymore.

SLAM the pool, eradicate the algae, and then see what kind of staining problems you have. You may have to just live with it until the end of the season.

 

[duraleigh]

I would suggest you wait until you complete the OCLT tomorrow AM. If you pass that, that confirms to me there is no algae in your pool.

Report that FC test in the AM and sit tight for a bit.

 

[mcleod]

You also need to understand that an AA treatment effectively reduces the free chlorine to zero and will continue to keep the FC too low until you’ve oxidized the ascorbic acid with enough chlorine. This is why you don’t want to do stain removal treatment late in the season or during the swim season - once the AA goes in, the FC drops to zero and algae can start growing within hours. It always best to address iron staining either super early in the spring time when the water is still too cold for algae growth or at the end of the season when no one is swimming anymore.

Ahhh! Thank you for the reply. Your response raises additional questions.
1) Would the outcome have been different had I used a sequestering agent after the AA treatment? Regardless of the sequence?
2) Is there a point where enough chlorine is added to the water to neutralize the AA? Would I have been able to determine that point from FC testing?