The biological filter is one of the most important parts of your aquaponic system. No matter how many fish you have, these will make the water a toxic trap in no time. Since you don’t have the space and amount of water you will need to keep your fish safe (unless of course, you own several acres with a lake in the middle), you will have to tweak nature a little so you can keep everything working.
Although there are a lot of commercial filter systems available, most of them require a certain amount of space, accessories and have an interesting price tag, if you know what I mean.
Making a biological filter is very simple, and costs a little fraction of a commercial one. Most important, this diy filter is very effective. As an example, take a look at this photo. You might think that I’m a lousy photographer, but the fact is that the pump decided that it was a little dirty and stopped working.
Since I was away for vacation, I found out a couple of days later. The water in my aquaponic system was completely dirty and very (very) stinky. After taking the fish out and putting them in a provisional tank (luckily, none of them died), I decided to put the aquaponic filter to a little test. After all, since I made everything myself, why not find out if it really works? Testing it in “normal” conditions is easy, but it is always better to have a “stress test”, even if it came as a random “gift” from nature.
Anyway, I cleaned and started the pump again and let it run for a couple of hours. The change was remarkable. In under 4 hours, the water was completely clear and the foul smell almost gone. I put a couple of fish as a test and they stayed well for the entire night, so I send everybody in the next day.
That showed me that this kind of filter is really effective, not to mention cheap. Also, you can make them out of several materials and adapt it to your acuaponic system in any space you have available at your home.
Another great advantage is that they are completely natural and you don’t have to tamper with them to keep them working. As a matter of fact, you just have to feed them and they will take care of themselves. That’s good news for backyard aquaponics.
There are several kinds of biological filters and the choice depends on the type of aquaponic system you have. The type I use is effective on everything I have tried, so I stand for it. However, testing is fun and you should do it every time you can, if it is safe for you and your fish.
After all, testing is what makes progress.