What is that scum in my reservoir? And how do I prevent and get rid of it?
Author: Matt LeBannister Date Posted:21 June 2017
algae, bacteria or fungi(nothing useful basically).
That scummy, sludgy buildup in your reservoir could be algae, bacteria or fungi. These organisms rob your reservoir of oxygen and nutrients, leaving nothing for your plants. They clog pumps and drippers, causing nightmares in the grow room. Regardless of what it is, it is usually caused by light entering your reservoir combined with higher reservoir temperatures.
How to get rid of them
Keeping your reservoir cooler, either with a reservoir chiller or by keeping your room cool, will make a huge difference. Covering your reservoir with either a lid or black and white plastic, white side facing up, will keep the light out.
Other tools to eliminate the sludge
You can also add hydrogen peroxide to your nutrient solution at each reservoir change to help eliminate the sludge. Cleaning your reservoir between crops is important to keep the sludge from returning. You can use a diluted bleach solution of one part bleach to five parts water, or there are many food-grade industrial cleaners available that will do the trick.