11. 9. 2019
Have you ever wondered what a day on an aquaponic farm looks like? Let me introduce you the activities involved. You will find out it´s nothing mysterious and difficult to understand. On the contrary.
So, what does a day in the life of an aquaponic farm worker look like?
The priority is a quality check every morning. This means performing routine analyses of the water and its pH, ammonia, nitrate and nitrite levels. The temperature of the water and air, as well as the humidity must also be checked.
The pH measurement is normally performed in one of two ways. The first is with the use of indicator strips. These are cheap to purchase but provide very inaccurate measurements. A deviation of even one decimal place plays an important role in aquaponics. This type of measurement is therefore risky. The second option is to purchase a digital pH meter. Such a meter guarantees a very precise measurement. However, over time, the instrument must be recalibrated, which can make it costly to purchase.
In my opinion, in this case, saving money is not worth it. I would strongly recommend directly purchasing a good quality pH meter. If you don´t, you run the risk of losing your entire production, with the final damage being far higher than the initial purchase price of one.
Ammonia, nitrites and nitrates can be measured by chemical reactions. No laboratory is required for this type of measurement. All you need are small testers for individual compounds. A common procedure is to mix some of the test water with chemical compounds and wait for the reaction. The result is evaluated according to the enclosed colour scale instructions.
Little note - if free ammonia is found in the aquatic environment, the fish are unable to excrete their own, which leads to their poisoning. Ammonia is toxic to fish and its values should therefore be kept at zero. If it shows a higher number, there are two options: 1) Reduce the rations. Ammonia levels increase when fish are fed. (This is the same as dead fish in the aquarium. It is precisely because of the release of ammonia that we have to remove them. Similarly with perishable feed.) 2) Increase the efficiency of nitrification (for example, by adding bacteria). We then check that everything is normal and inspect the fish. If they are active and look healthy, everything is fine.
Measurement of air temperature and humidity is possible with commercially available gauges. Due to high air humidity it is better to choose waterproof devices. The water temperature is measured with a thermometer. Personally, I prefer the traditional ones, but digital ones are not that bad.
It´s now time to talk about the routine care of the system. The health of the plants and fish should be observed. The fish must be physically active and look healthy. Plants, their diseases and pests, will be discussed in the upcoming “Aquaponic Phytosanitary” session.
Then the seedlings are collected and prepared. If plants are harvested, it is necessary to add new seedlings. To optimise this process, proper planning and timing is required with regards to the planting of individual plant species. After all, a mature lettuce consumes many more nutrients than a young seedling. If we harvested the whole crop at the same time, the nutrients would not be drained sufficiently, the water would not be thoroughly filtered, and in the worst case this could result in fish mortality.
In the following article we will take a closer look at my acquaintance and my first experience with aquaponics and the construction of outdoor systems.
Aquaponic is the Answer
- Kristián Božik