In this video, Lars answers a question from one of our readers where she asked,
“I have been collecting rain for my garden for the past two years. I was wondering what the best treatment is to keep the mold away. At the bottom of the barrel, it becomes black fairly quickly. Will moldy water hurt my garden?”
This is a great question and something that concerns a good number of people.
The main thing we wanted to point out is that it is not actually mold, but instead is merely sediment that has settled in the bottom of your rain barrel. The black “gunk” that builds up in the bottom of your rain barrel could be from leaves, dirt or other various debris from your roof that washes down into the barrel. Even with a screen on top of your barrel, this debris can still slip through and settle at the bottom.
This sediment will not hurt your garden, and it is okay if the water is not perfectly clear.
One way to get rid of the sediment is to simple rinse out your rain barrel at the end of the season.
Thanks for a great question, Susan. We hope this cleared some things up for you.