Pool stain in deep end that won't go away (now confirmed iron!)

Jump to latest Follow Reply
kstough

kstough

Active member
Jun 7, 2019
43
Ozark, AL
Update: thanks to @mguzzy I have confirmed the spots are iron stains. What is the best/easiest/cheapest way to get rid of this small area of stain that’s around 6x4’? Will I need to wait to treat until after SLAM is complete? Will the stain come back next time I need to SLAM (I read on here that it can)?
———————————————————-

We had algae/pollen all over bottom of pool when we took off our safety cover a couple weeks ago. We scrubbed and vacuumed but there is one area that the stain has not come up. I've tried putting a chlorine puck on it for several minutes and feel like it didn't make much of a difference. We are currently on day 4 of SLAMMING the pool so I would have thought the higher chlorine levels would have lightened the stain. We didn't have any metal items in the pool that lead me to think it could be an iron stain. The weird thing is that when we removed the pool cover the area that is still stained was one of the least soiled areas in the pool. My fear is that is is somehow on the other side of the liner....possibilities?


TFP Test Kit Results:
FC 12.5
CC 0.5
CYA 30 (not TFP—result from store)
TA 70
PH 7.5 (before SLAM)
Salt 3000

What to do?Screen Shot 2021-04-26 at 9.38.44 PM.pngScreen Shot 2021-04-26 at 9.39.03 PM.pngScreen Shot 2021-04-26 at 9.39.14 PM.pngScreen Shot 2021-04-26 at 9.39.27 PM.png
 
Last edited:
You've made fantastic progress in 4 days! I'm not an expert but I'm sure one will be here soon to help you. Until then, continue with slam.

What kind of filter do you have?
 
  • Like
Reactions: kstough
kstough said:
The only algaecide we used up to that point is Regal algaecide and it said “A non-foaming, non-metallic 60% strength polyquat algaecide.” Wouldn’t that mean it doesn’t contain copper?
Click to expand...
Yes as it says "non-metallic". Polyquat 60 types are the only ones we ever suggest using, and they're more a preventative helper rather than a algae killer.

Maddie :flower:
 

Enjoying this content?

Support TFP with a donation.

Give Support
Update: thanks to @mguzzy I have confirmed the spots are iron stains. What is the best/easiest/cheapest way to get rid of this small area of stain that’s around 6x4’? Will I need to wait to treat until after SLAM is complete? Will the stain come back next time I need to SLAM (I read on here that it can)?
 
I passed the OCLT last night! What a great feeling. I’m going to keep higher SLAM FC levels today just for good measure and then let my FC levels drift back down and get my CYA up to 60.

Now time to buy and crush up a lot of vit c tablets for those iron stains...
 
  • Love
Reactions: Snoobug
I don't think you are going to be able to do just a localized cleaning and have the stains removed permanently .. the iron is in the water and you really need to deal with it at the level of the whole pool. The staining is the sign that tells you that there is Iron in the water at a high enough concentration to cause stains. So I think you should prepare yourself to treat the whole pool and here's why. Ascorbic Acid (vitamin C or AA as we refer to it around here) will remove the stains from the vinyl and other surfaces, but it only changes the iron to another form so it will go into the water. Eventually it will change its form back and restain unless the iron is removed from the water. (I'm really trying to not dredge up high school chemistry, its painful for some;)). You can

1) Use AA on the entire pool to remove stains from the surfaces then drain and refill with iron free water
2) Use AA to remove the stains and then use a sequestrant that will bind with the Iron in the water...eventually you will have do it again, because the sequestrants will break down and the iron is released. Some people do an AA treatment followed by the sequestrant followed by a drain and refill to be assured of getting it all.
3) Use AA and then use a sequestrant that can be filtered out.. and to my knowledge there is only one product that will do that called Metal Magic.
4) Get the iron to go into the green form (your water turns green) and then setup a polyfil filter to filter the Iron out.

Then afterward you need to figure out where the iron is coming from. If you are on a well its likely in your fill water and you can set up a filter for that, or I have seen owners set up cistern systems that allow them to use rain water to refill their pools.

Let me send you down these rabbit holes for your information on how these work.

Ascorbic Acid Treatment - Further Reading

www.troublefreepool.com www.troublefreepool.com

Here is my recent-ongoing thread on treating Iron:

What I thought were old iron stains on my cartridge filters, is iron my water!

Hi all Amazingly I found no posts on the forum about this. So I was the victim of the dreaded Iron contaminated Clorox Pool Salt about 3 seasons ago. Apparently it was worse than I thought. There is a nice darker area in my mottled dark plaster in the deep end from salt additions from that...
www.troublefreepool.com www.troublefreepool.com

And another one:

Iron stains AA plus Metal Magic?

Folks, I'm on my 6th year of a crystal clear TFP pool but noticing splotchy light tan stains - classic iron. Failed the chlorine tablet test but passed vitamin C test with flying colors. I read up everything I can find on AA, citric acid, oxalic acid. I'm pretty sold on AA because of so many...
www.troublefreepool.com www.troublefreepool.com

The often referenced polyfill filter thread:

If you’ve got iron in your fill water, use Polyfill to remove it

EDIT: Found out this method only works if your iron is oxidized already, meaning it’s got a dull or bright green tint to the water, or a nasty brown tint. If you know you have iron in your fill water, but it isn’t oxidized yet, bring your pool to shock level and it’ll turn the telltale green...
www.troublefreepool.com www.troublefreepool.com

Good luck!🍀
 
Last edited:
  • Like
Reactions: Snoobug
I use vitamin C tabs all the time for iron stains .. just be careful because the vitamin C can eat up your chlorine! Make sure you are testing FC regularly while using the vitamin C.
 
I just went through this last week and mguzzy was spot on. Went from brown staining to a perfectly blue liner in a day.

It wasn't terribly expensive. 4 bottles of Robelle's mineral out sequestrant were the most expensive part ($40 total), and 5 lbs of citric acid ($20) along with a $5 bag of polyfill was all that it cost me outside of the normal rebalancing chemicals (which most of us have on hand anyhow). I didn't think my pool light or my entry steps were stained but wow at the difference afterwards. I'd recommend treating the entire pool and not just the spot. You will likely be surprised at what all might be stained.
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply