Overwatering: A Lesson for New Hydroponic Growers

Posted on November 18, 2013 by Travis Athougies

I recently set up a new flood and drain hydro system to start growing some things right outside my dorm room. Initially, I had a full-blown bell siphon which took a few weeks to perfect, but worked very reliably afterwards. I had about two square feet of growing space, and even set up a supplementary LED grow light to provide additional light.

Originally, I had planted five pea plants in my system, and they were doing fine for weeks. However, as I upped the nutrient concentrations in preparation for extreme vegetative growth, I noticed that I was soon having a bacterial growth problem. Clobs and clobs of white slime were slowly taking over my plants. Very soon, my plant leaves started to wilt, and I thought I would lose the whole crop.

To cope with the overgrowth, I added a quart of hydrogen peroxide to the system, and very soon, not only were the bacteria dying, but the plants were doing extraordinarily well. At this point, I realized that what the plants needed most was not water, but oxygen to the roots. Turns out that overwatering is as unhealthy for plants as underwatering.

The problem with the bell siphon that I had built was that it only started draining the water after it had already reached the top of the grow media, which meant that all of my hydroton got very wet, which made it the perfect breeding ground for bacteria. To fix this, I converted my flood and drain system to a simple drip system. Although this didn’t have as much of the “cool factor” as the bell siphon, I noticed that this system got rid of my bacteria problems, and also resulted in much healthier looking plants.

So what did I learn from this? Plants need oxygen too, and it’s really important that they get enough oxygen to their roots in order for them to thrive. Otherwise, your system will turn into a nice breeding ground for plant-killing bacteria.

Here are the lessons I learned: