A few weeks ago, I published an article entitled ‘Nitrogen and Potassium Absorption’ in which I explained the situation in the 175 litre aquarium regarding the Cyanobacteria growing within. In the article I explained that there was a possible link between the absorption of nitrogen and the absorption of potassium in plants.
However, after observing the tank for several weeks, I have found no connection between the absorption of these individual nutrients. After writing the previous article, I began dosing potassium twice a week. While there was a small increase in plant growth, it was not excessive. At the time of writing the previous article, the nitrate level in the aquarium was 10ppm. The nitrate is now resting at 5ppm, however, this is due to water changes rather than uptake by plants. Nitrogen uptake by plants would produce a gradual and steady reduction in nitrate, however, I only observed sudden drops in nitrate after performing water changes and thereafter, the nitrate level remained constant.
Phosphate and Nitrogen Absorption
After finding no apparent connection between the two nutrients, I continued to research the topic of nitrogen absorption and explore possible connections with other nutrients. Recently it has come to my attention that there may be a connection between phosphate and nitrogen absorption. One source discussed resolving potassium deficiency in plants by dosing phosphate. Although potassium was present, the plants were apparently unable to take it up due to a phosphate deficiency. It appeared that phosphate ‘facilitated’ the absorption of potassium.
I theorise that a similar process may happen with nitrogen and phosphate. Nitrogen, phosphate and potassium (NPK) are macro-nutrients that are required in large amounts by plants. All three of these nutrients may be linked in a complex process, however, I think it is more likely that all other nutrients are linked to the presence of phosphate than any other nutrient. Over the next couple of weeks, I will observe the tank and carefully monitor the nitrate level, while also dosing various amounts of phosphate. If there appears to be a link, I will conduct other experiments to determine if any other factors contribute to the observations.
I hope you have found this helpful and I will update you if any change is observed or progression made.