pH During Cycling in Aquaponics

November 26, 2023 by
Regen Aquaculture, Joe Pate
| No comments yet

The pH level is one of the essential factors in aquaponics. pH stands for potential hydrogen, a measure of the acidity or alkalinity of the water. It has a significant effect on the growth and health of both the plants and fish in the system. The acceptable pH range for aquaponics is between 6.0 and 7.5, while the optimal range is between 6.2 and 6.6. This range is ideal for plants within acceptable ranges for fish and microbes. If the pH level is too high or too low, it can cause stress to the fish and plants, leading to poor growth and even death.


When the fish excrete waste, it produces ammonia, which is toxic to the fish. Cycling is the process of establishing beneficial bacteria in the system that converts fish waste into nutrients for plants. Beneficial bacteria in the system convert ammonia into nitrite, then to nitrate, a relatively safe form of nitrogen that plants can use. The cycling process can take four to six weeks before the beneficial bacteria are established; during this time, the pH level can drop dramatically.

Low pH

During the cycling process, the pH level can drop below 6.0, which is too acidic for the fish and can cause stress. If the pH level drops too low, the beneficial bacteria cannot convert the ammonia into nitrite, which can lead to ammonia buildup and harm the fish.

High pH

On the other hand, if the pH level is too high, above 8.0, it can slow down the growth of the beneficial bacteria, which can affect the cycling process. To maintain the optimal pH range during cycling, monitor the pH level regularly and make adjustments as necessary. One way to do this is by adding a buffering agent, such as potassium bicarbonate, to the water to help stabilize the pH level.

In conclusion, the pH level is critical in aquaponics, especially during the cycling process. It is essential to monitor the pH level regularly and make adjustments to maintain the optimal pH range for the growth and health of the plants and fish in the system. Aquaponics can be a highly productive and sustainable way of growing plants and fish with proper monitoring and adjustments.

*This article was drafted with the assistance of ChatGPT, a large language model (LLM). All content was reviewed, modified, and revised by our editorial staff. The information here should be considered general advice only and not professional advice. For professional advice, you can schedule a meeting to Ask Regen Aquaculture.

Regen Aquaculture, Joe Pate November 26, 2023
Share this post
Sign in to leave a comment