Aquaponics Grow Media

What will my plants be growing in?

If you don’t know what grow media is allow us to explain. It is a term used to describe the material that is used for growing plants. Instead of soil we are using ‘grow media’ to plant our garden. This is what the roots will grow and expand in as your garden progresses.

There are many types of growing media that you can use for your aquaponics system however you want to be sure you know a few things before choosing.

First, the size of the media is important. We use 1/4″ to 1/2″ for our grow media because it tends to work the best. If you use rocks or other grow media that is out of this range you can run into some disadvantages. Media that is much smaller will not allow as much air space between itself (think sand). If the media is much larger it can be more difficult to plant and harvest easily plus surface area is reduced.

Generally there are two options to take with grow media:

We highly recommend you go with hydroton which is round, expanded clay pebbles. It works great, easily available, and it is pH neutral which means it will help your plants up-take the nutrients.


Another grow media people use is local gravel or rock. Be careful if you take this route because sometimes the rock will have high levels of limestone and other minerals that will affect your pH. This can lead to nutrient lock-out which means your plants will grow poorly or not at all.


Our main goal is to help you grow. If you choose to get rock locally, make sure you are educated so you make the right choice. As mentioned before rocks can have things such as limestone on them which will effect your pH.

The best way to check your local rock is to get a jug or cup full of normal household vinegar. Place your handful of rocks into the container. If you see that the rocks appear to be bubbling then it’s likely to have a high pH. In this case find another option.

Hydroton is our favorite option for a good reason. Expanded clay is not very heavy compared to rocks and it is pH neutral. Additionally it is easy to plant into, clean and sterile. If you are trying to do things as easy as possible we recommend just going for the hydroton.

Another great thing we recommend is to meet in the middle. By that we mean go with both local gravel/rock and hydroton. This is actually a great option because it reduces your cost on hydroton. You can line the bottom of the grow bed with gravel then fill the rest with hydroton.