Using Gravel in Hydroponics

Some of the things that you might not often think about as being useful in hydroponics are very simple, common materials that have some application to a garden, things that are found in nature, that can be used either to feed plants, shelter them, or provide pH value or for any number of other uses.

How about gravel?

Suppose you have some of the stuff lying around. Can you use it in a garden?

Some growers do use gravel in hydroponics. Here are some steps to consider if you're going to make use of any kind of gravel in your garden.

Structural Issues

When you’re thinking about traditional farming, you might think of gravel as lying on the ground, maybe between plant rows. In hydroponics, growers often use gravel for a type of grow media. That means they fill cups or pots with gravel, and set plant roots inside. Then they expose that area to nutrient-rich water. So one of the first things to think about with gravel is how the hydroponics structure will contain it.

Weight Issues

To be very concrete about it, you're going to have to evaluate whether gravel is a good choice considering the weight of the stuff. Even small amounts of gravel can add up to a lot of weight, and that can really put a strain on the loadbearing portion of your hydroponic garden, whether that is made of PVC, wood, or other materials. There are a lot of lighter grow options, so that's one way to figure out whether you should use gravel or not.

Figure Out How Water Will Run

You also have to think about how water will feed your plants when you put them in gravel.

The issue is that gravel, especially larger gravel, and is very high-drainage. It doesn't hold or trap water in the way that other media such as rockwool might. So you'll need to plan for water to drain quickly. Some growers have used gravel with drip or flood systems. You have to find a way to get your irrigation system to deliver the water into the gravel area and make sure the plants get enough.

Looking out for Silt and Contaminants

For one thing, you'll have to wash the gravel before you use it, to minimize the contaminants that will get into the plant environment. Also, over time, you're going to want to look for any evidence of silt or other contaminants mixing with the gravel to block up small openings in your irrigation tubes or pipes.

For more on everything that you might do with hydroponics, keep an eye on Dealzer as we continue to talk about the biggest issues facing growers today.