Iron AND algae in pool!


New member
Sep 7, 2019
West palm beach florida

New pool owner here, Intex 18x48 with a sand filter to be exact. After spending weeks of the dreaded leveling and setting it up we were SO excited to finally get our pool up and running and thought it would be easy sailing going forward. Little did we know, that wouldn’t be the hardest part yet :cry:The whole process has just gotten worse once we filled our pool with our well water. Once it was filled we noticed it was high in iron. We have been trying different ways to filter the iron water without using chemicals because I didn’t want to mess it up more...Including the polyfill in 5 gallon bucket trick. We have waited a few days and that even doesn’t seem to have worked. The water now after all this is so dark, basically black! I noticed the bottom had a bunch of crud on it, so I tried the vacuum approach and when I look at the Crud getting stuck in the vacuum it’s dark green. So now I think we have algae!

I’m at such a loss. I don’t know what the best solution is to take. I have been nervous about shocking it since the water does have iron in it, I have heard that just turns the water darker. But now I’m pretty sure we have algae too. So, dark mast iron algae water without any chemicals yet. What do we do?! Beside throwing it away and giving up :cry::cry:


TFP Expert
Platinum Supporter
May 23, 2015
Tucson, AZ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
You need to get a test kit. Everything that is taught here STARTS with you understanding your water chemistry. Without a test kit, you are essentially operating blind and you will continue to fail.

Test Kits Compared

I would suggest EITHER a K-2006C from Taylor OR a TF-100 with XL option from They both use Taylor reagents and they will work for what you need. You can probably get the TF-100 faster since the seller is very close to you.

While you’re waiting for your test kit to arrive, I suggest you leave the black swamp alone (or add half a gallon of plain, unscented, no additives, not-splashless bleach per day) and do some reading -

ABCs of Pool Water Chemistry

SLAM Process

The good news is you can tackle the algae first and then deal with the iron, no need to stress about trying to deal with both. The algae problem is the more urgent one to solve.
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