45l black rectangular water reservoir
Size: 55cm (L) x 36cm (w) x 38cm (h)
How to Keep your Hydroponic Reservoir Cool
One of the more annoying problems we deal with as hydroponic growers is keeping an oxygenated root zone at the perfect water temperature. It’s crucial to squeeze as much yield out of our plants as possible and minimize the potential of disease and infection. However, keeping your hydroponic reservoir cool can be a challenge.
This bumps up the temperature of the nutrient reservoir, which increases the temperature around the root zone. Because of this, the amount of dissolved oxygen in the root zone is lowered. When you combine these factors with plants growing faster in a hydroponic environment, you’ve created the perfect storm for oxygen deprivation. And when that happens…you open yourself and your grow up to pathogens like pythium.
For best results, you want your air temperature to be higher than your water temperature. Typical ranges are 23.9-26.7C for air temperature, and 20C or lower for water temperature.
Even though roots grow better at the slightly higher temperatures of 21.1-23.9C, you would be inviting in pathogens and root diseases that thrive at these temperatures as well.
So, How Do I Cool My Hydroponic Reservoir?
There are a variety of good ways to cool down your reservoir, ranging both in price and how annoying they are to deal with on a daily basis.
Regardless of the method you choose, you have to ramp up your cooling efforts in the warm summer months.
Paint Your Reservoir
Darker colors absorb more heat. If your reservoir is made of a dark plastic, consider painting it a lighter color – preferably white – to reflect some heat. Using something as simple as white spray paint can do the job and knock a couple degrees off of your reservoir temperatures.
Keep It In The Shade
This is a really obvious tip, but I feel like I had to mention it. If you can minimize the amount of light hitting the reservoir itself, you’ll be minimizing the amount of heat that is transferred to your nutrient solution. Keep it in a shady area of block the surface with cardboard or aluminum foil.
Increase The Size Of Your Reservoir
Many hobby hydroponic growers use smaller reservoirs which are exceptionally prone to temperature fluctuation. By building or buying a larger nutrient reservoir, you can add some stability to your temperature without building or buying any other cooling materials.
As an added bonus, your pH and ppm will remain more stable as well due to the larger volume of water.
Bury Your Reservoir in The Ground
If you’re growing outside, you can dig out the ground and bury your reservoir. The cool, dark environment below the surface of the soil will keep the reservoir exceptionally cool. You’ll almost never go into danger zone temperatures in the root zone if you use this method – but it does require a lot of effort.