Iron Staining and Polyfill: Check my plan

[superdave5599]

Last fall, at closing I attempted to remove iron by using AA, which did lift the stain nicely, then lowered the water level as low as I dared to dump as much of the iron-laden water out, then I refilled back to just under the skimmers for the winter, and of course topped off when I opened the pool. I'd thought I'd identified where it was coming from (exposed edges of the metal sides at the skimmer) and taken care of it, but staining has returned. I think maybe my fill water has more iron than I thought. In fact, over the winter, I got around to replacing the whole house filter and getting the water softener fixed. Turns out, the filter housing was empty, but coated with iron! Softener wasn't doing anything at all. So that fill-to-skimmers was with water that hadn't gone through a filter, and wasn't softened. I also forgot to recharge the softener and change the house filter before topping up the pool for the season, whoops!

Anyway, here is my plan:

Currently, the water lever is actually above the skimmer due to so much rain in just a few days! (I wish I'd dumped a bunch of iron water before, and used this to refill, but alas, I had no idea.)

So after reading several threads, I plan to:
Neutralize any chlorine (I'd been letting it drift down via lower SWG settings, and rain) left with peroxide.
Lower the PH (been riding closer to 7.8, but I didn't really think it mattered much up to now and reading that higher PH levels can encourage iron to precipitate out)
Treat the full volume of water with AA.
Dump off some of the iron-laden water as I lower the level to closer to normal.
Stuff the skimmer with Polyfill, and also maybe use a sump pump in a bucket filled with it, too, to expedite the process.
Slowly bring the chlorine level back up to the lower end of the range for a bit.
Clean the polyfill as necessary until it seems the iron is reduced.
Bring the chlorine level back up to desired levels.
Going forward, I'll stay on top of the house water filter better, and top-up water will go through a bucket of polyfill.

Question on the PH-During the polyfill phase of this, do I want to keep the PH lower to keep the iron in suspension more, or let it raise up to encourage the iron to get caught in the polyfill?

Anything I'm missing in all this?

Many thanks!

 

[duraleigh]

A lot of this forum is about accurate testing. I would get an iron test of from the pool store and post results here.

Fixing the softener will go a really long way towards curing your issue. It will take a while but it's a cure......not just a stop gap measure

 

[Mdragger88]

If it were me I’d do the polyfill method with slam level fc and filter out as much as possible then afterwards proceed with the AA treatment- it sounds like you’re trying to do two things at once or backwards?
If you attempt to raise fc after you just did aa treatment to get the iron to show itself you will bring all the stains back/make new ones- so filter what you can then treat the stains and exchange water/add sequesterant etc.

 

[superdave5599]

If it were me I’d do the polyfill method with slam level fc and filter out as much as possible then afterwards proceed with the AA treatment- it sounds like you’re trying to do two things at once or backwards?
If you attempt to raise fc after you just did aa treatment to get the iron to show itself you will bring all the stains back/make new ones- so filter what you can then treat the stains and exchange water/add sequesterant etc.

Except, that won't lift the stains, right?

I figured i need to get the iron back into the water before I can filter it out!

 

[superdave5599]

A lot of this forum is about accurate testing. I would get an iron test of from the pool store and post results here.

Fixing the softener will go a really long way towards curing your issue. It will take a while but it's a cure......not just a stop gap measure

I took a sample of both the pool water and fill water to the pool store for testing, and both showed very low levels of iron... However the stains lifted very quickly upon throwing in the AA as described in other threads.

I've read a bunch of the threads on the polyfill today, and found comments that the pool store testing for iron is as subjective and suspect as any of the other tests, unfortunately.

 

[Mdragger88]

Except, that won't lift the stains, right?

I figured i need to get the iron back into the water before I can filter it out!

The slam level fc brings the iron out of suspension which you then remove with the polyfill.
After you’re clear as a bell you then allow fc to fall and proceed with all the steps in at AA article to remove any stains.
At the end of the AA treatment you can then either replace as much water as possible with iron free water then sequester for assurance
or
simply sequester if you have deemed your fill water to be the culprit and omit the water exchange.
Its not a one time solution if your fill water is the culprit, you will likely need to do this dance again down the road once levels become too high.
You may or may not remain dependent to some degree on sequesterants to keep stains at bay.

 

[superdave5599]

The slam level fc brings the iron out of suspension which you then remove with the polyfill.
After you’re clear as a bell you then allow fc to fall and proceed with all the steps in at AA article to remove any stains.
At the end of the AA treatment you can then either replace as much water as possible with iron free water then sequester for assurance
or
simply sequester if you have deemed your fill water to be the culprit and omit the water exchange.
Its not a one time solution if your fill water is the culprit, you will likely need to do this dance again down the road once levels become too high.
You may or may not remain dependent to some degree on sequesterants to keep stains at bay.

So to make sure I'm understanding your explanation, I should raise the chlorine to encourage the rest of the iron that may be free-floating in the water, to settle out of suspension, with the goal that it'll settle into the polyfill.... THEN go after the stains with the AA treatment?

Once I've added the AA, I could keep going with the polyfill as I raise the chlorine again, hoping to capture that iron, too.... Yes?

 

[Mdragger88]

To clarify- the polyfill/slam method may result in more stains so its best to wait to remove stains after this process is complete

 

[superdave5599]

Rereading comments... "After you're clear as a bell..."

The water itself is clear, no murkiness or strange color noted against unstained parts of the liner (e.g. there are a couple places where it seems like something like a pool toy or a leaf or something was sitting there while the iron precipitated onto the liner, so now there are a few spots without the staining, or less stains.) Also, it is primarily the flat surface of the shallow end that is most affected, the vertical side walls and slopes to the deep end are much less affected. So the parts that are for whatever reason unaffected, look fine and the water against them looks nice.

I suppose it doesn't hurt anything but time to raise the FC and let it drop while I have the polyfill in there; though as I'm thinking about this further, it just seems like I need to lift the stains and then try to catch that iron... If that makes sense.