"Flushing" - Explained

What does it mean to flush a reservoir? And why is this a good thing in hydroponics?

Flushing a reservoir actually does several things, and knowing more about this process will help make you a better gardener.

Nasty Buildups

Over time, different kinds of solids tend to build up in hydroponic reservoir water. One simple one is algae -- if you see green stuff clinging to the sides of your plastic reservoir, you may have an algae problem. But algae isn't the only kind of buildup that can occur. Excessive nutrients or other solutions put build up in the water as slimy scaling on plant roots. Some types of debris can also get into the water and make it more dense and murky. Bacteria can build up in the water too.

Flushing the reservoir is an easy way to get rid of all of these contaminants. You're basically wiping the slate clean and putting in fresh water to give plants a second wind. This is very much like emptying and refilling a fish bowl -- you're taking out that cloudy and murky water with its buildup and making everything nice and clear again. And that can be very good for plant roots.

Adjusting pH Value

pH value is another thing that changes over time. As you add nutrients and other things that reservoir water, pH value changes. Plants generally thrive in a pH of five to 7. You may see this going to low or too high.

One of the things that growers often recommend is to use ‘pH up’ solutions on the water to raise the pH when you flush it. That means the new reservoir water is automatically pH-adjusted.

Adjusting Plant Feeding

Besides sanitation and pH adjustment, there's another reason why growers flush a reservoir. This is often done late in the cycle, near the flowering stage.

Think of this type of reservoir flushing as getting plants a “last meal” before harvest. Growers often make radical changes to nutrient strategies at the last minute. They may have been going along with a pretty neutral nutrient package with just enough nitrogen and potassium and other elements to nurse plants. Suddenly, at the end, they'll flush the reservoir and dump things like creatine and bone meal into that last cycle of water. This is in order to get plants to bulk up and really produce harvests.

Having a better idea of these in-depth strategies can help you to get more out of each pant. Take a look at Dealzer for more vital information on hydroponics and everything that goes into it.