A few weeks ago, I posted an article entitled Cyanobacteria and Nitrogen Deficiency, in which I explained the current situation in the 175 litre aquarium. At the end of that article I promised to approach the ‘problem from a scientific point of view’. That way, I could attribute any changes in the tank to the addition of Flourish Nitrogen.
It has been several weeks since then and very little has changed, regarding the Cyanobacteria. I added the Flourish Nitrogen in small amounts (2.5-5.0mL) over the course of about a week. Once the Nitrate level read 10ppm, I stopped adding the Flourish Nitrogen. It became clear that the plants were not absorbing the Nitrogen as expected. During the following couple of weeks, I tested the Nitrogen level on a regular basis but there was no change and the Nitrate level remained at 10ppm.
Nitrogen and Potassium Absorption
It is now almost two weeks later. During the two weeks that I was observing the Nitrate level, I developed a theory that perhaps the Nitrogen could not be absorbed by the plants because another nutrient was absent. This lead me to do some research, during which I discovered that Nitrogen can only be absorbed in the presence of Potassium.
So, I preceded to purchase a bottle of Flourish Potassium which I will add to the tank over the coming weeks.
If the information I gleaned from my research proves to be correct, I should observe the Nitrate level progressively decrease as I add more Potassium to the tank. As I mentioned in the previous article, I will aim to keep all other levels in the tank constant, so that if a change in the level of Nitrogen is observed I can confidently attribute it to the addition of Potassium.
I hope you have found this helpful and I will update you if any change is observed or progression made.