In Aquaponics the water parameters must remain in the appropriate range. By water parameters, we refer to the 3 molecules of the nitrogen cycle, the oxygen concentration and the pH. Today we will focus on the pH.
I will give you key information in order to manage it easily. pH fluctuations can have a dramatic impact on the fish, the bacteria and the vegetables. Generally speaking, the bacteria prefer a pH that is slightly high (above 7). While some vegetables prefer a pH below 7. In Aquaponics we deal with a whole ecosystem. Therefore, we try to maintain the pH close to the neutrality that is to say around 7. It is possible to increase the pH with different techniques. We can use natural elements such as egg shell or seashells. Those will add minerals into the water and slightly increase the pH. If you are looking to increase it more dramatically, baking powder is what you need. In other words bicarbonate sodium or even better, bicarbonate potassium.
Limestone into the media will impact your aquaponics pH
I would also like to highlight the fact that the aquaponics media must is of massive importance. We use the vinegar technique to check the limestone presence into the media.
How to decrease the pH
Many people use pure acids such as citric acid and phosphoric acid in order to decrease the pH. It can be risky, please don’t add it directly in your aquaponics system. Only use it on a seperate tank to prepare the water that you will then add to your aquaponics system.
GH and KH
In this video you will learn what the KH (Carbonate Hardness) is and the GH (General Hardness). Please understand that KH is having a buffering effect. It acts like a sponge into the pH evolution. Without being to scientific, pH is actually a representation of the ions H+ and OH- into the water. If you have an aquaponics system, you must be able to analyse your water pH. And determine if it’s a basic or acidic pH. Then, you must be able to regulate and control the pH in total safety for the ecosystem. You can take advantage of the pH drop to increase the aquaponics water mineral concentration. And therefore offering calcium, magnesium and other ions to your plants. You can also test the KH of your water. Regulate this parameter in order to take advantage of the buffering effect.
Reverse osmosis and peat
I don’t necessary recommend to use aquarium keepers techniques such as reverse osmosis. It’s a costly and non eco-friendly technique that waste water and energy. Peat can still be an option to decrease the water pH but it takes a bit more time and color the water.
If you have any question please leave it in the comment section below. We can continue the discussion there.
You will probably be interested to discover my six steps to build and manage an Aquaponics system. Click here to access for free! Thanks and good reading 🙂
