There are so many kinds of growing media you can try for your Aquaponic system. But there are some things you need to look out for while you are choosing your growing media for your Aquaponic system. First and foremost, you need to be highly specific when it comes to rock size. We suggest you use a media that is within eight millimeters and sixteen millimeters in size. If you happen to find rocks with sizes outside of this range there will be quite a number of disadvantages so don’t say we didn’t warn you.
If your media is really small then there won’t be enough air space in between your bed. On the other hand, if the media is relatively bigger the surface area will be greatly reduced which makes incorporating plants particularly difficult. Your options would have to include hydroponic expanded clay or you can also use a local crushed rock media. It’s also very important that you take extra precautions with the rock you come up with because some of these rocks may have increased levels of limestone and some minerals that have a high pH in them can result in a nutrient lockout. (Click here to know how pH impacts the accessibility of nutrients to your plants)
There are several rock media types that may already be available to you like shale, scoria, and river-stone among others. There are people who have discovered that local crushed gravel or rock media have a high level of pH. One good example is limestone; limestone can cause your pH level to shoot up. Having a high pH level can be a considered a drawback in an Aquaponic system (See how pH impacts the accessibility of nutrients to your plants). Therefore if you are unsure of your media you want to use, you can drop it in a cup or jug filled with ordinary household vinegar. After immersion, observe the rocks if it shows visible bubbling or if it releases bubbles from the rock then there is a very good chance that the rock has a high pH level. Your best option is to find another rock or look for other alternatives. It’s also worth mentioning that gravel or rock media can be extremely heavy. Therefore, you need to carefully plan out its support when building growbeds as well as their stands. The one great thing about rock media is the fact that it is easily available and comes with a very cheap price.
Your expanded clay is very light, it has a neutral pH and it comes in convenient bags. Expanded clay is very easy to plant. Cleaning and sterilizing aren’t going to be a problem if you are using expanded clay. Perhaps this is going to sound too good to be true, but it is. Perhaps the only downside to expanded clay is that it can be very costly. So if you are contemplating about getting expanded clay to use as your media you have to thoroughly weigh its advantages and disadvantages. However, if you want it quick and if you have the resources like finances then you should go for the expanded clay. But if you are concerned about the expenses thinking that it is too costly or if you are willing to invest some time to create strong supports and moving as well as cleaning your media then our suggestion is you go to the rock media.
There are those who like to go on the road in the middle and so what they do is they fill the bottom portion of their bed with rock or gravel and then fill the second half with expanded clay. The costs are cut significantly and so does the weight. It also makes sure that you have a good media for planting and harvesting. With this method, you get the best of both worlds at half the price.
The third edition of the Outdoor Aquaponics Magazine shows the results of our trial testing of four distinct growbed media that we’ve mentioned here. In this edition, you will also have access to a lot of general information about what to look for with your growbed media within your local area. (Click here to learn about Common Guidelines on Fish Stocking)