The aquaponics system is a marriage of hydroponics and aquaculture. However, in most cases, you will require some sort of grow media for your plants to grow. The only exception to this rule is if your setup involves floating the plants on a raft like platform over a nutrient filled solution. If you’re not doing this, then you’ll need to be aware of the choices you have regarding grow media.
An important factor to be aware of is the type of media you will be using. This could be clay pellets, gravel, etc. Whatever you decide to use, you need to use media that has a particle size of about 8mm to 16mm. The size is important. If the particles are too big, you will have less space to grow the plants. If the particle size is too small, there will be less air space in the media.
One highly recommended grow media is expanded clay. It’s clean and easy to use. However, it is expensive. A cheaper option would be to use rocks. There are many types of crushed rock media commercially available for aquaponics systems. You will need to keep an eye on the pH value of the water when trying out these rocks. Some rocks such as limestone can raise the pH value of the water quite high.
There is a quick way to test if the rocks you are going to use will affect the pH value. Place a few rocks in a clear plastic bag and pour some vinegar in the bag. If the rocks start bubbling and you see bubbles being released from the rock, then you may wish to choose another type of media.
Expanded clay pellets do not have such issues. They are also lightweight and porous. That means your whole setup will be lighter and there will be less need to have very strong supports in place for your system. A media that uses rocks will be heavy and needs to be well supported.
Another advantage of clay pellets is that they do not absorb water effectively. That means it is ideal for a system that uses a flood and drain method of supplying water to the plants. With clay pellets, water must constantly be pumped back and forth so that the plants are receiving the water frequently and don’t dry out.
The key point to note when choosing your grow media is that it must allow the water to drain well. If the water does not drain well, the plants’ roots will get waterlogged. Once that happens, the roots will start to rot. Porosity is very important when choosing your grow media.
Since aquaponics has been steadily gaining popularity over the years, there are several companies that produce media ideal for aquaponics systems. It would be best to invest in a good media to ensure that your system is really good. Treat the cost as an investment which will pay dividends in future.
You may wish to learn more about aquaponics before taking the plunge. There are aquaponics guides on Amazon if you’re interested. If you’d rather learn from videos, there is an awesome video series at www.Aquaponics4you.com. Do check it out and you will be an expert in the subject.