New Pool Owner With High Iron Manually Removing Iron

[labdi01]

Marie -

I have a question for you...

Now that we've removed all the iron from the pool using the makeshift filter, we were left with some liner/skimmer staining. I read the ascorbic/citric acid treatment sticky - but you suggest immediately following up with a sequestrant. Do you think I could run my sump pump/batting filter during the ascorbic acid treatment in order to trap and remove the metals rather than having to sequester them?

[CarlD]

Hi,

I just noticed something I've been wondering about: You said you were adding calcium and you said you have stains on your liner.

So..if you have a vinyl liner are you aware that you do NOT need calcium in your water? Calcium's only for concrete/gunite/plaster pools.

[labdi01]

POOLSTORED!! Didn't use it yet - I'll return it. Does Calcium contribute to staining (it is a metal).

My staining is light - but now that I'm clear - it's visible!

Think my jerry-rigged filter would work rather than a sequestrant to catch the metals as they come off the lining/fixtures?

[chem geek]

Your batting is catching fine particles of iron and rust (iron oxides). What kind of filter do you have? I suspect that a DE filter or a high-quality cartridge filter would be able to catch such particles as well, but perhaps not a sand filter.

There is a commercial product you can buy called The Slime Bag™ which filters down to around 1 micron so even finer than a DE filter. Sounds like you've found something homemade that works quite well, at least for metal particles.

Metal sequestrants hold metal ions suspended into solution. They don't do anything for fine particulate matter which is what you are filtering. No physical filtration will remove metal ions -- they are dissolved in solution just like salt dissolves in water. So even though you have removed most or all the particulate metal solids from your pool, you could still have metal ions and should have your water tested for iron. If it measures high (say, more than 0.3 ppm) then you should still use a metal sequestrant to prevent staining.

Some people have talked about intentionally shocking and raising the pH of iron-filled pool water in order to intentionally create rust that can then get caught in a filter, but such a process can also stain pool surfaces so it's not a foolproof method.

Richard

[labdi01]

Good Morning, Chem Geek.

I'm happy to hear from you.

I actually have a sand filter and I've been using DE in it throughout this process and it does capture a decent amount of iron. The makeshift filter and the sand filter usually produces the same level of staining when we clean/backwash them (like this am, the staining in both was a lighter yellow/orange after filtering for 12 hours with a visibly crystal clear pool).

Yesterday at the pool store, my iron registered 0 - but clearly there was still iron in there as we cleaned both filters twice since my store testing and they were stained both times, so I'm not sure what kind of range their "0-reading" has (if that makes sense).

Right now I'm doing an ascorbic acid treatment (in the circulation phase until tomorrow am), at which point I'll be adding DE to the sand filter and putting the makeshift filter in as I slowly add chlorine (bleach). I imagine if staining returns during that process (esp since I haven't quite figured out what 'bringing it up slowly' means), that will tell me if I need to continue with sequestrants. I think on any level, though I certainly reduced the amount I'd need - no? It's just nice to see bottom for more than a day!

[labdi01]

Chem Geek -

Forgot to mention, that we had been using the Slime Bag for a while early on. When we were using sequestrants and got the pool clear/green, then I tried to bring CL level up 'slowly' at that point and went right back to opaque brown.

I also used the Slime Bag to filter our fill water along with a hose pre filter (put Slime Bag over both), then filled a bucket and poured bleach in the bucket - turned brown.