Filtering Iron


New member
May 26, 2020
Stillwater MN
I have read a lot of the info on this site about filtering out iron. My current "opening" process for my intex above ground has worked great. I am in the process of having a new in ground pool installed and am wondering if my current process to remove iron will work at that scale. The new pool should be about 25K gallons (vs my intex at ~7K).

Here is what I have done for the last few years:
1. Setup Pool
2. Fill with Well water (goes through my water softener).
3. Add 1 gallon of SPLASH pool shock (liquid).
4. Turn on filter/pumps

About 5 minutes after dumping in the shock, the pool starts to look greenish, 5 more minutes and its brownish. Filter runs for about 18 hours (I backwash it a couple times) and we have crystal clear water. I then proceed with balancing ph and adding salt. Then I pretty much do nothing for the rest of the summer (other than monitor). Once I move to my new pool I plan on adding CYA. I have never had iron staining and I never see the iron again after that initial shock / filtering.

My question is, on my new much larger pool, given how seemingly easy it is for me to remove the iron, should i spend $1,500 - $2,000 buying water to have it trucked in for an initial fill or am I safe to use my well? I don't know what my iron level actually is, but we don't have iron staining in the house so I feel like it can't be super high...

Any thoughts are greatly appreciated!

Initial green color (5 minutes after Shock):

Brownish color (10 minutes after Shock):

Brown backwash a few times:

Clear pool after filtering for 18 hours:


Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
Houston, Texas
It may take a little longer to clear but it should work just the same. You can also get some poly-fil pillow stuffing and put it in the skimmer basket to catch iron too. Once it is dirty you can rinse it out and use it again.


Gold Supporter
Aug 26, 2016
Berks County, PA
Wow, does your story ever bring back some rather unpleasant memories! Have you looked into possibly using a "Pool Magnet" product that gets added to the water? When we first had our pool built we had water trucked in from local hydrants, etc. to fill most of the pool. I finished the last few hundred gallons or so with our well water.

Needless to say -whether or not the issue was with the fire company's tankers or the hydrant lines in town, our beautiful new plaster wound up having unsightly brown stains all around the pool at each level that a load of water ended. And, of course, the water was all brown. THEN, a few days later (I could still rant thinking about this..) a letter from my pool builder arrives indicating that while the pool is filling, be sure to add "Pool Magnet". Would have been really nice to know ahead of time. Oh well, water over the dam (or more like through the bottom drain). Pool Magnet is supposed to tie / bind up the iron and other metals (others here could explain it much more accurately) so as to prevent any staining. Just a thought if you've not tried something like that.

Have you ever actually had your well water tested for the presence of metals? I wish you the best with the new in-ground installation but would strongly recommend that you check into all the options before you'd wind up with the situation I was in. When we had the pool completely renovated a few years ago, there was no way I was going to use local fire company tankers to bring in water. We used Aqua Duck Water Transport. Water was crystal clear. Hope all goes well for you! ?
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