One of the biggest questions i usually receive from a budding aquaponist is “What is the best media to use in my grow bed?” Although an important question, what I think is best may not suit the needs of everyone. So let me breakdown some important factors in considering media.
There are certain characteristics that one looks for when determining what type of media to use in a grow bed of the aquaponics system.
- It must be ph neutral, meaning that it can not affect the ph balance of the water.
- It must not “add” anything to the water that is detrimental to either fish or plant life
- It must be a porous material
- Must not degrade or decompose as it must withstand numerous or constant water “baths”
- It should be light weight, depending on how the grow beds are structured and setup
Important to any hobbyist will also be the material cost. This will be one of the largest expenses in setting up a system of any size. I will list some of the more popular in relation to cost.
Many professional aquaponists swear by the use of LECA (Lightweight Expanded Clay Aggregate) or Hydroton. It is very durable, porous, light weight (about half the weight of stone), and ph neutral, making it the media of choice to many if not most professional run operations.
To the hobbyist, it may not be the most practical choice mainly due to expense. It is one of the most expensive media’s on the open market. Filling a 4′ x 4′ grow bed 12″ deep can cost upwards of $500.
Expanded shale is growing in popularity in the United States mostly because of it being locally mined, thus reducing some initial cost. It is very porous, easy to handle, and lightweight. It is heavier than LECA but still about 25% less weight than stone. Expanded shale is less expensive than LECA, but for the same size bed as above, one can still expect to pay around $400
Growstone is relatively new to the market. It is a man-made substrate manufactured using up to 98% waste materials. It largely consists of recycled glass bottles, keeping them from the landfill. It is very durable, porous, and lightweight (about the same as Hydroton). This is an easy to handle product and is about 50%-60% the cost of LECA. Our 4′ x 4′ grow bed should cost less than $300 to fill 12″ deep.
The least expensive grow media would be crushed or river stone. Of course it is also the heaviest of the materials and great care must be taken to insure than any stone used was not mined around or include any limestone. Limestone, even a little, can severely upset the balance of ph in the water tank.
Wherever you are in your quest to start in aquaponics, Grow media has to be one of the first decisions you make before adding fish or plants. It is an important decision, but as a hobbyist, you must determine the best product that fits your budget.
If you are just starting or thinking about setting up an aquaponics system, get all the education you can before taking a leap into an expensive setup. Many pre-made systems for the hobbyist can cost upwards of $2000. But you can cut a lot of costs by building your own system, small or large.
Make the decision to learn the basics and research what is best for you. Get with a mentor or learn from someone that has been doing it successfully for some time. We have classes organized for those considering aquaponics or those who are ready to take the leap. Check out our upcoming classes, where we will discuss more in depth picking the right media for your needs along with many other Aquaponics Basics.