I had an iron problem last summer and I have a bit of one now for reasons I'll start a separate post on later. What i'll say next may sound strange, but I know it can work. I actually did it by accident. I added quite a bit of water to the pool after some heavy duty cleaning and vacuuming to waste after I put in my paver pool deck. Anyway, when I added about 600 gallons of water, later in the day, my water turned nice and green. Clear as it could be, but emerald green. I mistook it for an algea bloom since my FC got a bit low. So..I brought the FC up to around 20 ppm since my CYA was set for a SWG. In about 4 hours, the pool was clear and blue. No dead algea percipitate like I would have expected. I backwashed the filter even though the pressure didnt change. What came out was the orange-ist, rusty water with big chunks of orange particles I ever saw. After more research, I figured out it was the iron in the water. One of the ways water is treated for iron is to highly chlorinate it, let it form a percipitate, then filter it out with sand. This is exactly what I had done on accident. If you cant get the iron to sequester as well as you like, you might try to shock the pool to 20 ppm or so, filter, and see if it clears. Don't nuke it, of course, but a mustard level shock for you CYA level might do the trick. You cant just add little chlorine. All that does it START the process. You really need a shock level for it to work. I did it 3 times last summer, and it worked every time. This summer, I'm going to get a Hydro Pure Metal Trap and see if that helps.
From blue to green in 96oz
- Thread starter Tim23
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What bk406 suggests can work, but isn't reliable. Just as often as working it can cause the iron to deposit as stains on the pool instead of particles that can be filtered out. It would be nice if people who are willing to risk staining can experiment with it can see if we can come up with a procedure that can be replicated by other people. Just remember that for the moment there are some serious risks.
Do you have 1st hand knowledge of the reliability where someone tried it and it didnt work, or conjecture?JasonLion said:
You're right, it is a risk, but i wouldn't call it serious. Well, if some stain is serious to some one, I guess it's all in how you look at it. It will work, and I have found it reliable, YMMV. As I said, water treatment plants have used super chlorination and sand filtration for years to clean up iron out of water. As far as a DE or cartridge filter, I couldn't say. I have a sand filter and I know that works.
As far as staining from the percipiate, I really have not noticed that it make staining worse. In my case, the water cleared in a few hours, so i dont think it hung around all that long. If you have a white plaster pool, then maybe the stain risk is too much. But, for a vinyl liner that is not a solid color, it might not be a big issue. I know I have some iron stains on my liner, but you have to look real close to see them. If it were white plaster, then it might be unsightly, but not harmful.
I wonder what would happen in a cartridge filter situation? Once the water clears just take out the cartridges and wash them? I wonder what level of iron it actually removes from the system? You said you did it 3x last year, did each time have a diminishing return to indicate your iron content was dropping?
I may be wrong here, but if you keep adding the sequestrant and then bringing back the chlorine level and then add the sequestrant and so on, won't over time you remove or get the metals out of the water to where it won't be needed unless you add a bunch of water or do a water change out?
I believe that was said in a earlier post. It makes since but sometimes I have no since because I loose my mind! LOL
Tim
I believe that was said in a earlier post. It makes since but sometimes I have no since because I loose my mind! LOL
Tim
dayhiker said:
Worked about the same everytime, really. But, in my case, my fill/top off water had iron in it, so i never really took care of the root problem. Everytime I added water, I was adding iron back. This year, I bought a Metal Trap filter, so I'll see how that works. I will not have to add near the water I did at the end of last season. I had a leak that was fixed this spring, so my water use will be much less.
Tim23 said:
I'm not sure that would work. The sequesterant puts the metal back into solution. Dissolved/sequestered metals will not filter. The metals need to be oxidized and soluble for them to form particulates that can be filtered out. That's the way metal filters work. They oxidize the metal then filter the particles. Cheaper ones (<$300) use disposable cartridges. Once they filter a given ppm or metal, they no longer work. Whole house filters use rechargable elements and get backwashed like any other sand type filter.
I wish someone else would try it and see what happens
First hand knowledge.bk406 said:
Stains require an AA treatment: a fair bit of work, $ for the chemicals, and at least a week not swimming. Call that serious or not as you please.
I just reserve the word serious for things like liner failure, pool floating out of the ground, etc, etc. A little elbow grease and a couple of bucks isnt serious. But to each his own :-D
So is the wording "metal out" is what, a sequestrant? Doesn't it separate the metals from the water so it can be filtered or just change the color? Sorry if that sounds stupid. :?
Tim
Tim
Tim23 said:
Metal Out is something that sounds good on a label, but isn't really what's happening.
Well, the term "Metal Out" is more of a marketing term, really. A sequesterant is really a big old molecule that surrounds the metal ion and, in effect, "removes" it. The metal is still there, it's just surrounded by a chemical so that it doesnt drop out of solution. The idea of oxidizing the iron is that it WILL drop out of solution, form particulates, and will be filtered out. But as Jason pointed out, there is a risk that the dropped out metal will stain before it gets filtered. I suspect the best luck is had if the metal content is fairly low (say <1 ppm), a fairly small volume of pool water (15000 gallons maybe) and a pretty quick pool water turover (6 hours?). Thats all conjecture on my part, no empirical evidence.
Edit: Melt in the sun posted while i was typing
Edit: Melt in the sun posted while i was typing
Melt In The Sun said:
Last summer when I was first dealing with this I needed another qt of sequestrant from what I'd ordered online. I went to the local pool store and asked for sequestrant. I got a blank stare. I tried to describe what the stuff does. The reply was, "You mean you want stuff that keeps the iron in your pool, but prevents it from staining?" Yes. "Why would you want that? We don't have anything like that, but I can sell you some stuff that gets rid of the iron and gets is out of your pool." This was done somewhat indignantly. SHe handed me metal free. I read the label, and replied, "Yeah, this is a seqeustrant, it's just what I'm looking for, thanks." I'm not sure she grasped the implications of what I had told her.
I pulled it out of my earfrustratedpoolmom said:bk406 said:
Interesting phrase....
dayhiker said:
Now thats funny right there, I dont care who you are!
(my apologies to Larry)
I think the main point about intentionally precipitating metal is that it's one thing in a vinyl pool where metal staining is less likely to occur, but quite another in a plaster (or even fiberglass) pool where metal staining is a not uncommon reality. As I noted earlier in this thread in this post, I've been handling a metal staining (more like a discoloration) problem myself. I had let the pH drift up during the winter since the winter rains were diluting the water and lowering the TA and CH so I wanted to maintain the saturation index. The pH went up to around 8.1 and apparently caused a yellow discoloration in the deep end that I presume was iron staining.
When I lowered the pH, the stain slightly faded so I added PolyQuat 60, let the chlorine get to near zero, added ascorbic acid, and the stain lightened up. After a day, I added a phosphonic acid based metal sequestrant and the water became a little cloudy though cleared up in a few days. The stain/discoloration also completely went away (a few much older darker spot stains only slightly lightened, but I didn't expect them to get handled as they are 4-7 years old). That's the good news. The bad news was that my chlorine demand (after initially getting rid of leftover ascorbic acid) was very high at 3-4 ppm FC per day where normally I'm at around 1 ppm FC per day (I have a mostly opaque pool cover).
So this process started last Saturday, with the metal sequestrant added on Sunday and as of yesterday (Wednesday), the 24-hour chlorine demand has dropped to 1.5 ppm. I had raised the chlorine level in the pool (to an FC that is around 25% of the CYA level) to accelerate this process as we are going away on vacation/business and I wanted a more normal chlorine demand for our house sitters. I'm probably just breaking down the metal sequestrant which sort of defeats the purpose, but I won't use the sequestrant anymore and instead just keep the pH in check. I also have about 60 ppm Borates in the pool so my pH doesn't get very high even at higher FC levels.
I do wish there were another way to remove iron from the pool. Yes, there is RO that will remove everything and there is ion exchange but that's not practical with pool volumes. The iron is not coming in from the fill water, but from some steel mounts that are holding stainless steel bars in the pool. My initial use of Trichlor pucks 7 years ago in a floating feeder rusted nearby mounts when the tethered floater parked itself nearby. These mounts continue to rust. Is there any way to stop this? Some sort of sanding and sealant? Or was there some sort of thin coating that is now gone (i.e. more like galvanized steel than stainless steel, though I can't imagine that's what the PB used since galvanized would mean zinc coating -- the bars themselves are clearly shiny stainless steel, but the mounts are much duller looking).
Richard
When I lowered the pH, the stain slightly faded so I added PolyQuat 60, let the chlorine get to near zero, added ascorbic acid, and the stain lightened up. After a day, I added a phosphonic acid based metal sequestrant and the water became a little cloudy though cleared up in a few days. The stain/discoloration also completely went away (a few much older darker spot stains only slightly lightened, but I didn't expect them to get handled as they are 4-7 years old). That's the good news. The bad news was that my chlorine demand (after initially getting rid of leftover ascorbic acid) was very high at 3-4 ppm FC per day where normally I'm at around 1 ppm FC per day (I have a mostly opaque pool cover).
So this process started last Saturday, with the metal sequestrant added on Sunday and as of yesterday (Wednesday), the 24-hour chlorine demand has dropped to 1.5 ppm. I had raised the chlorine level in the pool (to an FC that is around 25% of the CYA level) to accelerate this process as we are going away on vacation/business and I wanted a more normal chlorine demand for our house sitters. I'm probably just breaking down the metal sequestrant which sort of defeats the purpose, but I won't use the sequestrant anymore and instead just keep the pH in check. I also have about 60 ppm Borates in the pool so my pH doesn't get very high even at higher FC levels.
I do wish there were another way to remove iron from the pool. Yes, there is RO that will remove everything and there is ion exchange but that's not practical with pool volumes. The iron is not coming in from the fill water, but from some steel mounts that are holding stainless steel bars in the pool. My initial use of Trichlor pucks 7 years ago in a floating feeder rusted nearby mounts when the tethered floater parked itself nearby. These mounts continue to rust. Is there any way to stop this? Some sort of sanding and sealant? Or was there some sort of thin coating that is now gone (i.e. more like galvanized steel than stainless steel, though I can't imagine that's what the PB used since galvanized would mean zinc coating -- the bars themselves are clearly shiny stainless steel, but the mounts are much duller looking).
Richard
chem geek said:
I do know that in structural steel construction they make a zinc rich paint that is applied to field connections after welding has burned off the galvanizing. I haven't a clue what it costs, but you could probably call for a fabricator in your area. There is also a high end paint used in corrosive environments called TNEMEC. Note that it's spelled cement backwards. It's probably hard to get just a quart of the stuff.
chem geek said:
You attribute the clouding to the sequesterant? I've used Jack's and never saw the clouding, so i'm just curious. Do you think there are certain conditions in the pool that make this clouding worse?
Would an EDTA based chelator cause clouding as well?