Iron has precipitated, now what...

deanr

Member
Jun 18, 2014
14
Wadsworth, OH
I have an above ground pool, ~18K gallons and a cartridge filter. I also have well water, with significant iron. I have a whole house filter for the iron, but that apparently isn't enough to keep iron out of the pool fill water. I normally add a sequestrant at the beginning of the season when I open the pool, and normally don't have to add much water. I get the sequestrant from my local pool store, and it is a house brand that I don't have an ingredient list for. Normally, no problems, generally have great looking pool water with pretty easy startups. Generally we get enough rain the last few years that there wasn't much fill water added. Instead, I had to keep removing water from the pool as it got too full from all the rain. This, of course, was wonderful since it kept my troublesome well water usage to a minimum.

This year, things went wrong.
1. Due to an error on my part, I inadvertently drained a lot of the water from the pool so had to put ~10K gallons in from the well.
2. Added sequestrant and let it circulate for 36 hours before adding chlorine, as normal. I don't remember how much I put in, but thinking back I don't think I put in enough
3. There was a lot of junk on the cover that ended up in the pool at startup, so water was very dark. I hit it hard with chlorine, ~22ppm FC
4. Unexpectedly, there wasn't a high chlorine demand, so it took a while for levels to come down. Pool was still not clear, but not brown.
5. TA was high, ~225ppm, so started aeration treatment with muriatic acid
6. At this point, water turned brown and opaque. No appreciable Cl demand, and lots of iron on paper towel in skimmer.

Long story short, I have a lot of iron that has been oxidized by various means and is now precipitated in the water. I've been running the filter full time, with polyplus in the skimmer basket, with some other filtering media over the skimmer basket etc trying to collect the iron. It has improved, but has been a couple weeks of filtering and feels like it will take forever to clear up the precipitated iron.

I've been researching the posts on iron control, and most are dealing with stain removal. There isn't much discussion I've seen of dealing with heavily discolored, cloudy water due to oxidized iron other than how to filter with polyfill etc.
My goal up to this point has been to remove as much iron as possible now that it has precipitated, but I'm reaching the point where we would like to have clear water without waiting for the rest of the summer. We have significant staining on the liner, but I'm not so concerned about the staining for now.

My question is what is the best thing to do to move from brown, cloudy water due to iron to clear water and happy kids? I see three paths:
1) Filtration. This is what I'm doing now, and its very slow going
2) AA treatment. In the forums this is generally discussed in terms of removing stains. But perhaps it will also drive precipitated, suspend iron back into solution where sequestration will work?
3) Sequestration using Metal Magic, or Stain-x (available at my pool store). I understand this sequesters iron that is not already oxidized, but I don't know how it impacts iron that is already oxidized.

Any advice much appreciated!
Thanks,
Dean
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,250
Key West, FL
I have an above ground pool, ~18K gallons and a cartridge filter. I also have well water, with significant iron. I have a whole house filter for the iron, but that apparently isn't enough to keep iron out of the pool fill water. I normally add a sequestrant at the beginning of the season when I open the pool, and normally don't have to add much water. I get the sequestrant from my local pool store, and it is a house brand that I don't have an ingredient list for. Normally, no problems, generally have great looking pool water with pretty easy startups. Generally we get enough rain the last few years that there wasn't much fill water added. Instead, I had to keep removing water from the pool as it got too full from all the rain. This, of course, was wonderful since it kept my troublesome well water usage to a minimum.

This year, things went wrong.
1. Due to an error on my part, I inadvertently drained a lot of the water from the pool so had to put ~10K gallons in from the well.
2. Added sequestrant and let it circulate for 36 hours before adding chlorine, as normal. I don't remember how much I put in, but thinking back I don't think I put in enough
3. There was a lot of junk on the cover that ended up in the pool at startup, so water was very dark. I hit it hard with chlorine, ~22ppm FC
4. Unexpectedly, there wasn't a high chlorine demand, so it took a while for levels to come down. Pool was still not clear, but not brown.
5. TA was high, ~225ppm, so started aeration treatment with muriatic acid
6. At this point, water turned brown and opaque. No appreciable Cl demand, and lots of iron on paper towel in skimmer.

Long story short, I have a lot of iron that has been oxidized by various means and is now precipitated in the water. I've been running the filter full time, with polyplus in the skimmer basket, with some other filtering media over the skimmer basket etc trying to collect the iron. It has improved, but has been a couple weeks of filtering and feels like it will take forever to clear up the precipitated iron.

I've been researching the posts on iron control, and most are dealing with stain removal. There isn't much discussion I've seen of dealing with heavily discolored, cloudy water due to oxidized iron other than how to filter with polyfill etc.
My goal up to this point has been to remove as much iron as possible now that it has precipitated, but I'm reaching the point where we would like to have clear water without waiting for the rest of the summer. We have significant staining on the liner, but I'm not so concerned about the staining for now.

My question is what is the best thing to do to move from brown, cloudy water due to iron to clear water and happy kids? I see three paths:
1) Filtration. This is what I'm doing now, and its very slow going
2) AA treatment. In the forums this is generally discussed in terms of removing stains. But perhaps it will also drive precipitated, suspend iron back into solution where sequestration will work?
3) Sequestration using Metal Magic, or Stain-x (available at my pool store). I understand this sequesters iron that is not already oxidized, but I don't know how it impacts iron that is already oxidized.

Any advice much appreciated!
Thanks,
Dean
I think you are doing all you can right now. I would not bother with attempting the AA treatment. Have you tried Sequa-Sol? You can order online. I would try the Sequa-Sol combined with the continued filtration. I'm surprised it hasn't settled on the bottom, so you can vacuum it to waste. Are you running the pump on low speed or high?
 

deanr

Member
Jun 18, 2014
14
Wadsworth, OH
I've been running the pump on high full time, cleaning the filter each time the flow rate drops on the return. I've vacuumed a couple times, but the pool was so cloudy I couldn't see what I was doing. This morning it was clear enough that I could see piles of something precipitated on the floor near the edges of the pool (couldn't see the middle of the pool well enough to know what was going on there). I'm guessing it was iron, but can't say for sure.

Perhaps I should leave the pump off overnight and let things settle, then try vacuuming again before things get stirred up?

To be clear, I've not put any sequestering agent in since that first dose at startup. That dose was probably both inadequate, and now been oxidized away with the high chlorine levels I'd been using. I figured I'd wait on the sequestration until I had given up on filtering.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,848
SW Indiana
I agree with FPM that you are probably doing all you can do right now. Get as much as you can out and deal with the rest when the pool is cleaner.
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,250
Key West, FL
I've been running the pump on high full time, cleaning the filter each time the flow rate drops on the return. I've vacuumed a couple times, but the pool was so cloudy I couldn't see what I was doing. This morning it was clear enough that I could see piles of something precipitated on the floor near the edges of the pool (couldn't see the middle of the pool well enough to know what was going on there). I'm guessing it was iron, but can't say for sure.

Perhaps I should leave the pump off overnight and let things settle, then try vacuuming again before things get stirred up?

To be clear, I've not put any sequestering agent in since that first dose at startup. That dose was probably both inadequate, and now been oxidized away with the high chlorine levels I'd been using. I figured I'd wait on the sequestration until I had given up on filtering.
Question, what condition is the filter in? Was it new for this year? How old is it? I had a client who had soooo much iron in the water the filter was orange/brown and completely coated to the point it wouldn't filter anymore. That's why I ask about the age and condition of the cartridge?
 

deanr

Member
Jun 18, 2014
14
Wadsworth, OH
The filter I'm using is brand new this year (I learned this lesson the hard way). It hoses out easily when I clean it. I can definitely tell that it catches iron, I just don't have enough experience to know if I'm just scratching the surface of the iron problem or if I'm making appreciable headway.
 
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frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,250
Key West, FL
Okay, sounds like you have a handle on it. I always use Sequa Sol on my clients even when it has oxidized and it typically helps within 24 hours. Might be worth a shot. ;)
 

deanr

Member
Jun 18, 2014
14
Wadsworth, OH
Thanks! Question - should I try letting things settle with the pump off overnight, or keep it running on high? It is definitely catching material on high, but perhaps some settling time wouldn't hurt either...
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,250
Key West, FL
Thanks! Question - should I try letting things settle with the pump off overnight, or keep it running on high? It is definitely catching material on high, but perhaps some settling time wouldn't hurt either...
I would actually run it on low and see if you can get it to settle, then you can vac it out... Good luck!
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,848
SW Indiana
I’d keep it running and try to blind vacuum to remove as much material as you can. When you vacuum, you’ll probably stir a lot of stuff up that the filter might grab as well.