Water parameters are massively important for your fish health. Fortunately, in the aquaponics nitrogen cycle the bacteria are transforming the fish poo (ammonia) in nitrite and nitrate.

One of the main difference between backyard aquaponics and intensive agriculture/aquaculture reside on the fact that we create an environment where living creatures are living in comfortable condition. Unlike the classic food production system we aim to not spray pesticides. Instead, we offer the best environment to our ecosystem to avoid the stress and the apparition of disease.
Water parameters are massively important for your fish health. In the aquaponics nitrogen cycle the bacteria are transforming the fish poo (ammonia) in nitrite and nitrate.

Ammonia and nitrite toxicity in aquaponics

Ammonia and nitrite are highly toxic for the fish and we want to make sure we keep them at the lowest concentration possible (below 0.5ppm).
The impact of those toxic elements on the fish are very wide. Among them we can note the following:

  • Reduce oxygen in blood
  • Affect:
    • Liver
    • Retina
  • Strange behaviour (swim on the side, gasping behaviour)
  • Brown gills and blood
  • Poor feed conversion
  • Poor growth
  • Fast swimming
  • Fast breathing
  • More disease
  • Increased mucus production
  • Darkening of body coloration

Seeing this long list of terrible effects we can understand the importance of keeping ammonia and nitrite low for the fish welfare!

keep those concentration low

One of the solution to avoid ammonia and nitrite is to have a very well adapted biological “filtration”. I mean a nice population of bacteria able to transform those toxic elements in nitrate. Therefore, the trick is  to keep a low density of fish compared to the population of bacteria (exact ratio available in the free aquaponics training).

Plants are still in need of nitrate which is their main nutrient so you still need a certain quantity of fish in your ecosystem 🙂
Indeed, most fish species will accept 0.5ppm of ammonia or nitrite for a limited period of time. However, they will appreciate and live more comfortably a concentration between 0 and 0.2ppm.

I recommend beginners to test the water once a week and to monitor ammonia and nitrite. If a pick is detected please stop feeding your fish, renew some water and during the following days decrease the fish biomass by fishing a few fish.

You will probably be interested to discover Jonathan’s six steps to build and manage an Aquaponics system. Click here to access for free! Thanks and good reading 🙂