FAQ: What do I do about iron sediment on the bottom of my swimming pool?


FerriTab Use in Pools Before and AfterQuestion: This is my first season as a pool owner. Following the advice of our local pool service, I filled my 27ft above ground pool with our well water which is extremely hard and has lots of iron.  They sold me a filter that attaches to the end of a garden hose that was supposed to filter out most of the minerals.  They also had me use chemical called suspend to precipitate the iron, then shock.  I’ve done the suspend then shock procedure twice and although I get lots of iron precipitation at the bottom of the pool, when I vacuum, I can see the iron blowing right back into the pool. I’m trying the Ferri iron tabs now.  So far the water looks brown and I see iron at the bottom of the pool. Should my sand filter be filtering out the precipitated iron? Especially when I vacuum, I can tell that the iron goes straight through the filter and back into the pool. Any advice would be appreciated!


The sand filter should be able to filter the iron out of your water with minimal coming back into the pool. If you are seeing it back in the pool I would look at your filter and sand. Do you know when the last time your sand was changed? We recommend every 3-5 years – or when indicated by your filter not working as effectively as it should. If the sand is clogged and channeling (basically areas where the water can run through the sand without actually filtering – down the sides etc) the iron could get through. You could also have a crack in one of the internal pipes or fingers at the bottom.

You can always vacuum on waste to waste some of the water with the iron directly out of the pool. Of course you will have to top off the water with your hose, adding more iron back into the pool. As long as you add a ferritab when you add the new water, and check the filter sand it should catch the additional iron without too much issue.

Hope this helps!