Dissolved Oxygen Metering

by Mark
(Shippensburg, PA)

Since dissolved oxygen is important, is it a good idea to measure dissolved oxygen and maintain a certain level? I have never seen anything posted about that topic.

Answer: Mark- I do not believe they make a dissolved Oxygen meter....at least not for indoor gardening. There are two things you need to do to ensure your nutrient solution contains enough dissolved oxygen. First, make sure your nutrient solution does not get too warm. Cool water is capable of holding much more dissolved Oxygen than warm water.

To demonstrate this, fill a clear glass with cold water and let it sit for a couple of hours. As it warms up, you will notice little air bubbles forming on the inside of the glass....lots and lots of them. This should give you some idea of how much Oxygen your nutrient solution will loose if you let it get too warm. In general, you want to keep it between 65 and 72 degrees F. If you are gardening in an unfinished basement, keeping the reservoir on the concrete floor will help accomplish this.

At the same time, do not give your plants ice cold water straight from the tap. This will shock the roots and I have seen this mistake kill an entire garden almost overnight.

The second thing you must do is keep at least one air bubbler in your nutrient reservoir. As long as the nutrient solution is at the proper temperature, the water quickly dissolves all the Oxygen it can hold. Finally, you only really need to do all this when you are growing your plants roots in standing water (Deep Water Culture). Other hydroponic systems provide Oxygen at the root level in different ways.

Beyond that, don't worry about measuring or metering the Oxygen levels in your nutrient solution. There are more important things to worry about....hope this helps you out Mark, and Happy Growing!