Such a thing as inline greensand filter add-on for pool?

[Swampwoman]

Hi all. I am a new owner of a well-water home (previously with swamp that is now a lovely, crystal pool thanks to this forum!)

To date, I've been using a hose filter or my fill water, using jack's magic pink stuff, plus culater, to manage the iron. I tried a semi/mini citric acid treatment to address the steps and some historic iron stains. Worked a little, (a lot on the steps, a little in the bad stains) but i brought the chlorine up too fast and/or did not have enough sequestrate, so iron has precipitated again. Because no one wants me to close the pool, I'm going to wait until fall to do a proper AA treatment.

Today, I discovered that my fill water is indeed connected to the water softener, so it's actually at .5 ppm instead of the 2 ppm native to the well. The pool water itself tests clear, which I presume you would expect with sequestrant (added full dose today and so doing did lighten the stairs.)

I've been reading up on general iron treatment and am learning about greensand.

My question is does anyone know of an "inline" greensand filter made for pools? I've read about the metal trap, but am not sure that would handle the volume the way I want (eg -- always!).

Alternately, has anyone ever added a bt of green sand to a sand filter? Or would that cause a world of unintended trouble?

Thanks for any thoughts or suggestions!
Cheers,
K

 

[CUTiger78]

greensand???

 

[Swampwoman]

Yes, it's a type of sand (green) that is coated with maganese (or something similar) that removes iron from water and is used in some water treatment situations/facilities.

 

[wetchem]

Had one at the hotel.
Iron was terrrrrrribbbllle there
http://www.appliedmembranes.com/iron11.htm

More than you want to know:
http://www.waterprofessionals.com/process-water/greensand_filtration.html

-wc

[EDIT] The links are for information about what a greensands filter is, not an answer to the question... I wouldn't have the fogiest as to where to order one for a pool. I think the one at the hotel was orginally from the local water treatment company... been over 20 years since I worked there and I don't remember exactly what that tag said on it! - getting old. [/EDIT]

 

[Swampwoman]

Thanks. I may call that company and see if they've deployed a system to treat the pool, but perhaps with the cost we should just add a full filter to the well instead -- the 80 degree limit would be the problem for doing it inline on the pool!

I was hoping there was a way to ultimately remove the iron in the pool water now that I have to keep sequestered. But I may just have to wait to do that until we need to replace the liner (it's 12 years old but actually looks quite good). At that time, I might truck in iron-free water -- probably cheaper than jack's magic forever it's vinyl and our water table is high-ish so I'm disinclined to drain it unless it's for repair/replacement purposes!

 

[duraleigh]

At that time, I might truck in iron-free water -- probably cheaper than jack's magic forever

That's the single BEST thing you could do for your pool. Iron laden water is problematic and one of the biggest headaches we see on the forum. The green filters work but seem to have very little capacity to service a pool. Other mechanical filters do not work at all.

Filling with iron free water, especially if you can refill with a whole-house water softener will give you unlimited ease of use in your pool and may make Jack a little sad but that's the breaks

 

[Swampwoman]

Thanks for confirming my suspicions! I am a reasonably intelligent human and my own conclusion has been either to buy stock in jack's magic or do the full drain and fresh start with the water.

My "softened" water still has .5 ppm iron -- just enough to cause staining, so I will perhaps wait until we sell our other house and then start at the root of the problem with an extra oxidizer like iron curtain for the whole house, then upgrade the liner, then fill with iron free water. In the interim, I guess I'll ride it out with AA at the end of the season and keep Jack happy

 

[JasonLion]

Greensand filters will work for removing iron. However, they are fairly expensive and work very slowly. You will need to feed them with a low flow rate feed, typically a small separate pump, put potentially an adjustable tap off the main pump. For most situations the costs are prohibitive.

 

[chem geek]

If your iron levels are high enough that they measured in tests and you want to physically remove the iron from the pool, you could try using CuLator®. It's expensive and we've had some mixed reports from people using it so it's too early for us to recommend it, but if you are willing to try it then it's an option for you. If you do use it, please report back with your results since we really want to get to a thumbs up or down on this product at some point.

 

[Swampwoman]

Hi Chem Geek. Actually, I am using CuLator and did read elsewhere that yours doesn't change color Guess what! Mine doesn't change color either!
However, maybe I should put it in a jug of water from my tap -- if it doesn't change water then and doesn't remove .4 ppm of the iron we'll know it's bogus!

Those test levels, btw, are from my fill water -- I cannot get an iron reading from the pool water itself - zero zero zero even the chelated reading. Presumably this is because it is sequestered right now?
And yet, those ARE iron stains on the steps, (per vitamin c and AA tests) and OLD iron stains on parts of the liner, especially in the shallow end.

I have new suspicions forming about the bottom of my steps...I noticed what might be "rust" in the tiny crevice between the molding guard and the edge of the step insert. I am wondering if some of this is leaching out when I pour chlorine in that area -- the round stains on the vinyl floor are nearby. I will continue to "investigate" (aka float around with a drink in hand and stare lazily at the pool steps

 

[wetchem]

Those test levels, btw, are from my fill water -- I cannot get an iron reading from the pool water itself - zero zero zero even the chelated reading. Presumably this is because it is sequestered right now?

If you are using the typical chemical based tests then your assumption is more than likely correct.
I have sequesterant in my pool, the Hach tests which are chemically based return a zero iron; however, when I a method that uses a flame in the analysis, I do get an iron result.

-wc

 

[Swampwoman]

Yes, I actually hijacked by husband's Hagen salt water aquarium iron test. It's a drop test and he generally considers it to be reliable (eg. his fish HOPE so
What kind of test uses a flame?

 

[wetchem]

The one I use is a laboratory instrumentation method: Flame Atomic Adsorption Spectrophotometry.
Not something typically found outside of testing labs.
There are other flame tests for iron; however, for pool water they are not practical.
-wc