What is runoff and why do I need to check it?

Runoff is the excess liquid that passes through your plant's root zone and substrate. For example, the runoff would be the excess liquid in the plant's saucer in a standard potted soil plant. Checking the pH and EC levels of this will help you understand how your plant is feeding.

Why check it, you ask? If you regularly check your runoff, you will ensure your plant is feeding correctly, and your pH isn't fluctuating. It is easy to check your runoff; it's the same as checking your nutrient solution before feeding. All you need is an EC meter and a pH Meter.

Ideally, your runoff pH and EC should be within 10% of the Nutrient mix.  If your nutrient mix had an EC of 2 – you would want your runoff between 1-8 and 2.2. If the pH of your nutrient mix was 6.5 – you would want your runoff to be between 5.85 and 7.1.  

If either of your readings are outside this zone – you've got a problem. If your EC in your runoff is high, chances are you are overfeeding your plant, and we don't need to tell you how catastrophic that can be! To combat overfeeding, flush your plants until your runoff EC is at your desired level.

If your runoff pH is out of balance, we recommend flushing until it's at the desired level. If your pH is too high or too low, it will cause a nutrient lockout, which will have a detrimental effect on your plant.

A simple step like checking runoff can save you from crucial mistakes that could cause you to lose your plants. If you weren't checking your runoff before, hopefully, you will now.