Slimebag

[ned8377]

Anyone had any experience using this to filter metal out of water? I've done AA and sequestrant but now it is staining the skimmers and jets etc so it is coming back. Do I need to wait for the water to turn brown or some other color before it can be filtered out? Thanks.

 

[JoyfulNoise]

I would start with polyfill stuffing in the skimmer basket. It's cheap and you can get it at any craft/sewing store (Michaels, JoAnn's, Hobby Lobby, etc). The SlimeBags are expensive and a bit of a PITA to hook up if you don't have the right parts.

You could also rig up a submersible pump and a 5 gallon lidded bucket with polyfill stuffing to act as a filter. However, the sequestrant is going to hold onto the iron so if your water isn't tea colored brown or very clear green, the process may take a long time.

 

[ned8377]

So, if I want to filter it out, I should just let it get worse until the water actually changes and then it can be filtered. I should not use AA and or sequestrant until I am through filtering, correct? To help it come out of solution, should PH and chlorine be raised?

 

[JoyfulNoise]

Ascorbic acid (AA) removes metal stains. In the case of iron, it reduces the Fe3+ ion (the stuff that causes rust and precipitates out as a yellow brown color) to Fe2+ which is soluble in water. The sequestrant (typically a phosphonate polyanion) then holds on to the Fe2+ ion and captures it until the sequestrant breaks down from chlorine exposure at which point it releases the iron. The oxidation of the sequestrant is a really slow process so this is why you can treat for iron, add sequestrant and the stains will stain away.

When iron is in the form of Fe2+, there is no amount of filtering that can remove it. It's only when it gets oxidized to Fe3+ by chlorine that it comes out of solution as microscopic precipitates which color the water a yellow/brown color. It's the Fe3+ form that can be filtered by the polyfill.

So if you did the AA treatment and sequestrant, you're basically stuck waiting for the sequestrant to breakdown and release the Fe2+ and then waiting further for that to be oxidized to Fe3+. It won't happen overnight or all at once unless you were to really shock the heck out of your pool with high levels of chlorine while simultaneously raising the pH to near 8.0. I would not recommend intentionally trying to precipitate iron because you can't control it and you could wind up with stains all over your liner. You can try the polyfill for now in the skimmer and see if it will capture anything. Otherwise you have to just wait it out.

Do you plan to close your pool for the winter?

 

[ned8377]

Yes, I do plan to close for the winter. The staining I have gotten is from some Clorox Salt I used. The Sam's Club website is full of reviews of people complaining about it. https://www.samsclub.com/sams/clorox-pool-salt/prod21063423.ip Thanks to TFP, I found out about it - too late. I did Natural Chemistry Stain Free Plus which is AA about 3 weeks ago and then put in Natural Chemistry Metal Free. I have now found out that ProTeam Metal Magic is better and have some on order. I kept my PH at 7.1 - 7.2 and gradually raised the chlorine but now that chlorine is correct for FC/CYA the staining is coming back. I've got to go away this weekend so can't mess with it right now but thought maybe leave it the way it is and I might be able to start filtering it next week instead of sequestering again. Does closing for the winter make a difference? Thanks JoyfulNoise.

 

[Swampwoman]

Hi Ned. The MM will likely clear the stains enough to get you through the season and still be able to swim. I think joyful asked about closing because it'd be a good time to then oxidize the iron and filter out...but give yourself a week or two before hard close to make sure you're gotten rid of any excess AA so it doesn't eat your winter dose of chlorine

Btw, slimebag does trump Polyfill in that it filters to 1 micron, which is ideal for oxidzed iron. You do have to buy the connector ring for the return inlet.

Bit if you're not on well so don't generally get any prefiltering benefit from buying it, Polyfill will get you close cheaper. So too will Duda Diesels disposable filter bags.

 

[ned8377]

But Swampwoman, I'm confused now. I thought AA made it so the metal could not be filtered out because you can't see it anymore after AA and nothing to filter. I thought that the shape I am in now with skimmers turning brown etc means I can filter it out. So, you are saying that AA makes it so the metal can be filtered out? Maybe what you mean is to filter out before the sequestrant. Is that it? When you say iron is oxidized is that what AA does to it? I thought that chlorine had oxidized it just like it does bacteria and that is where I am now.

 

[Swampwoman]

Forgive my lack of clarity.

If you oxidized the iron through slam levels of FC and then filtered, you may be left with more staining from the process and want to do AA treatment to then remove any staining, then sequester for the winter to tie up any residual iron.

I meant that you'd want to give yourself time to do all this as necessary before a hard close.

 

[ned8377]

So the iron can be filtered out when the free chlorine and pH are raised and it is oxidized. Iron cannot be filtered out after ascorbic acid or if sequestered. It has to be visible either in the water or staining surfaces. Is that correct?

 

[ned8377]

TFP really needs a separate category for metal and organic staining of pools in the forum.

 

[JoelWitt]

I agree. For me it is the #1 problem I have. I switched to the TFP method mid last season and my pool has been PERFECT all summer for the 1st time in 12 years. What a great site!

 

[Swampwoman]

So the iron can be filtered out when the free chlorine and pH are raised and it is oxidized. Iron cannot be filtered out after ascorbic acid or if sequestered. It has to be visible either in the water or staining surfaces. Is that correct?

I'm not 100% certain that *some* cannot be filtered out after AA but before sequestrant, as I'd never been "Unsequestered" enough to try.

I did once have a poster report filtering post AA treatment using a filter aid called FeriTabs. Have a read on his thread and see what you think Ferri-Tabs Review

Generally, if you can't see evidence of the metal, you're not likely to filter much of it. BUT if you do an AA treatment and DON'T follow with sequestrant, you WILL get staining back. For this reason, I believe that the parts of the metals tat fall out of solution after AA has dissolved it can be filtered over time, if that makes sense.

Metals/staining is a very complex issue and its quite difficult to support users through it via TFP because there are so many variables, products, product elements that are incompatible, etc. and most of us know what we know by collective trial and error. So it's a bit more difficult to arrive at advice that is "uniform enough" to express as a tutorial or with any true authority. Its something we struggle with as guides, just so you know. I've not yet figured out how to give anything other than ad hoc, situational advice