Invented by Dutch microbiologist Diana Walstad in the 1980’s, the Walstad Method was a discovery of using nutrient-rich soil instead of the normal gravel or sand that was used in aquariums to fuel live plant growth (Learn The Aquarium).

 

By layering soil and capping it off with either sand or gravel, plants have an incredible substrate for absorbing nutrients through their roots, rather than absorbing nutrients through their leaves with liquid fertilizers. Although liquid fertilizers are still very popular in the hobby today, the Walstad Method proves to be superior as plants are able to better benefit by absorbing nutrients through their roots, resulting in far better growth. This is why Walstad Method tanks, or sometimes just referred to as “Dutch Style” tanks, are often found to be lush and vibrant.

The Walstad Method also simply allows a tank to have a more balanced ecosystem. A well-established plant system acts as a form of filtration by absorbing dangerous chemicals like nitrate, nitrite, and ammonia that are caused by excess food decomposition and fish waste. Thriving plants also combat the growth of algae because they absorb more of the nutrients in both the soil and the water column (AquaGoodness). In some cases, if a tank has an ecosystem that is healthy and balanced, a mechanical filter is not even necessary.