Getting Rid of Iron

[Lily07132007]

After months of research I've exhausted all options and hoping someone with expertise can help. I am trying to figure out how to get the iron out of our pool water. Our pool turns greenish brown almost weekly, which we believe is due to iron (background below). We use a maintenance does of metal sequestering agent weekly. Is it possible the sequestering agent is just "wearing off" before the week is up? We've had the pool water tested and it's never been above .3ppm iron, and typically is at .1ppm iron, which I thought was within the acceptable limits. We've tried:

• Running metal traps recirculating through the pool
• CULator in the pump basket
• So many chemical products I can't even list

The water is generally pretty clear, as long as we keep the chlorine levels where they should be. When the pool water turns greenish brown, a container of stain free turns it back clear within minutes (which is why I think it has to be iron). We've tested for copper and always had a 0ppm result. We are unable to shock the pool without turning it brown, even with non-chlorine shock. We haven't had the heater running, so I don't think it would be a metal introduced by that.

We filled our pool with well water last fall and afterwards found out that our whole house iron treatment system wasn't functioning properly. We had a leak over the winter, so we lost a lot of that water (at least a third) and replaced the whole house system before filling. We've had the water from our house tested by multiple entities since then, and the iron in it is low (less than .1ppm).

Water test results (from local pool store) from yesterday:
FC 2.09
TC 3.27
CC 1.18 (yes I know this is high, see shocking problem above)
pH 7.2
Hardness 188
Alk 132
Cy 58
Copper 0
Iron .1
Phosphates 949 (again, know this is high, doing a phosphate treatment)
Salt 3125

I've spoken with multiple experts, companies, etc. I've reviewed hundreds of websites, blogs, forums on iron and haven't found a solution yet that seems to work. I've heard we cannot 100% drain the pool without risking compromising the pool structure, so replacing it with new water may not be an option. Has anyone every encountered a pool with similar problems before? Thank you!

 

[duraleigh]

Welcome to the forum

Iron is troublesome but manageable. Of course, your source water (the well) is the issue but I assume you have no other reasonable resource, right?

So, the solution is to start introducing iron free water through your whole house system. Confirm that your spigot from which you are filling the pool goes through your whole house system. Outside spigots are often bypassed so you need to know that first.

This may seem off the subject but it is not. You are going to have to wean yourself from that pool store testing and get your own good testing kit.....either the Taylor K-2006C or TFTestkits TF-100 (most prefer the TF-100) Those test results are probably not reliable and no one here puts faith in them. We DO put faith in your ability to test your own water.

Confirm that your refill source goes through the iron removal system. We'll all help you get your pool clear.

Off the subject but return that phosphate remover if you can.....that's a waste of your money.

 

[Lily07132007]

Thanks for the response. Right - well water is all we've got. We are currently filling from the in-house water. Our outside spigots DO go through the iron treatment system, but I've learned that the removal of iron relies on both the iron treatment system AND the water softener to remove all iron. Something about different size iron molecules - which our water quality guy explained in more scientific terms. The outside spigots do NOT go through the softener. So we fill with soft water from inside this house. We then add chemicals to increase the hardness of the water. Small price to pay to not have to deal with iron.

I do have a small testing kit at home which i use occasionally. It's a Guardex 4 in 1 that was left by the previous owners. I believe it tests all the same things except the hardness and the CYA. I also have all those strips for phosphates, salt, etc. I just assumed the store was more accurate because they have the fancy computer equipment. Why would it be unreliable?

I appreciate the info.

 

[duraleigh]

The outside spigots do NOT go through the softener.

You'll have to redirect them to get rid of your iron issue. Since you say you have tried everything else, I see no alternative if you want to truly fix the issue.

 

[Lily07132007]

You'll have to redirect them to get rid of your iron issue. Since you say you have tried everything else, I see no alternative if you want to truly fix the issue.

Sorry, that was background info. We are filling from IN the house, which DOES go through the softener. We figured if we got this mess all figured out, we could eventually run a new, special spigot from in the house to outside, just for maintaining the pool.

 

[duraleigh]

We are filling from IN the house, which DOES go through the softener

How long have you been doing that? If your softener is working, your iron problem should be solved as you are refilling with iron free water.

 

[Lily07132007]

We've been doing it since spring, whenever we need to add water. We think the problem is the existing water that went in in the fall when we had the liner replaced. That water did have iron in it, and we can't seem to get rid of it.

 

[duraleigh]

Whenever your pool turns brown from chlorine, you are precipitating iron into it's solid form and it can then be filtered out more or less successfully. Your "brown" episodes should be less and less over time. How are you chlorinating your pool?

I should add that when you put in sequestrant, you return that precipitated iron to it's soluble state, only to re-precipitate when the sequestrant wears out.

 

[Lily07132007]

I will say I think it's getting easier to turn the water back clear when it turns, and that it doesn't get "as brown" as it used to. But i don't know that the frequency has reduced at all. We chlorinate via the Intellichlor SWG, and I've been supplementing with Chlorine tabs in the skimmers. The intellichlor is brand new but since we couldn't shock, its been an uphill battle to get it in a maintenance state, hence the chlorine tabs.

So are you suggesting that we leave it brown to filter the iron out? Obviously it's a fine balance because we don't want it to stain the new liner or the fiberglass parts. We have tried a filter aid in the filter, to bring the filtration down to an even smaller particle size.

 

[duraleigh]

Folks here report some success using poly-fill stuffing in the skimmer to catch the brown iron particles. Your sand filter will also catch them.

I think you can be pretty confidant that, once precipitated, the iron will not stain your liner (but pool water with soluble iron can). I am not so sure about the plastic parts but I think the same principle applies.

So, yes. I would be tempted to try to filter out the visible iron and continue to refill with softened water. Eventually, there will be no iron left in your pool.

What does your water look like right now?

 

[Lily07132007]

Water is looking green-tinted since yesterday evening. Started in the deep end, but now is also in the shallow end. It's tempting to think the green is algae, rather than metal, but every time it looks like this it eventually turns brown, and then clears up right away with Metal Free. So the green seems to be the first step on the way to brown. Attached is a picture from a couple weeks ago, and another from before that, seconds after adding Metal Free. It's not this brown now...yet.

 

[pabeader]

Look up poly fill filter. Lucky that your iron is visible. Mine was never that way. It was only ever on the sides of the pool or in solution.

 

[Lily07132007]

Ok, i did find some info on that. I'll try it and report back. Thanks!

 

[duraleigh]

Assuming you are on a path to getting rid of the iron (it'll take some time), then you should focus on why you are shocking your pool so much.

TFP pools almost never need shocking.....they remain crystal clear all season. That's where your own testing (with one of the two kits I mentioned) will teach you even more about your pool and pool water chemistry.

Before you take that step however, you must pledge to yourself to be willing to learn what we teach and to stay out of the pool store......their help has gotten you where you are.....you can do better

 

[Lily07132007]

I actually haven't been shocking at all. The normal chlorine from the salt cell has been turning it brown. We've needed to shock to reduce the CC, but haven't been able to because of the iron situation. I'm actually surprised, beyond the brown from the iron, the pool water has been fairly stable. I've been incredibly hands on in this whole process and been doing my own research to determine and try possible solutions. We purchased a disaster of a pool situation and we've come a long ways in cleaning it up, with the iron being the last problem standing.

I am curious about the pool test kits. What is the difference between those kits and the one I have? It seems like what I have covers most of the same measurements and the items it doesn't measure, tend to be much more stable and so require less frequent testing. Obviously I would rather not spend additional money if what I have will get the job done.

 

[duraleigh]

I hear your skepticism. I hope you get a chance to read the hundreds and hundred and hundreds of posts on this forum that will perhaps change your mind.

 

[PoolguyinCT]

2 hours later water is recovered, 24 hours later water is invisible.

our town is using an auxiliary well for municipal water this year & pools are turning to coffee!! This pool merely topped off with an inch or so , after I fixed a located & repaired a return side pipe leak.

When I pick up my portable system I’ll snap a photo, 38k gallons of invisible liquid diamonds.

 

[PoolguyinCT]

liquid sequester was added & ascorbic acid.
Liner is now brown haze free & so are the white goods. Thank goodness since I replaced the liner last month.

I have his system shut down, and will leave the auxiliary system until I change his sand this week.

Think what you will about sand changes, severe mineral cases I change it, I like to be one & done.

 

[PoolguyinCT]

This is his next door neighbors pool, another fresh fill after 1 gallon of liquid chlorine & 5 minutes.

The municipal fill water did not have the tell tale haze either.

 

[Lily07132007]

Thanks! I put the polyfill in the skimmers last night. It was looking better this morning, but still some green in the deep end. Changed out the polyfill and keeping at it. Since it wasn't as brown when i put the polyfill in as it's been, i don't think all the iron is oxidized so there's probably still sequestered iron in there. I need to get my CC down so I'm planning to shock tonight, then i'll keep at the polyfill and see how it goes. Probably won't know for sure if all the iron is gone for a few weeks.