I think the nutrients are absorbed with the caulepra plants. Here is an article about the Mud filter. Let me know what you think.
The EcoSystem™ Method.
A unique filtration method based on sound ecology.
The Ecosystem Filtration Method is based on the principles of ecology and is a natural filtration system that simulates the environment found in coral reefs. It does not require a Protein Skimmer or activated carbon to purify the water. It keeps the water well oxygenated through the photosynthesis of Caulerpa and entirely eliminates the need for air pumps. Caulerpa can also be harvested and used as fresh, natural food for fish. In addition, Caulerpa prevents the growth of undesired hair algae by competing for essential nutrients.
The EcoSystem Filtration Method uses the end products of fish metabolism and fixes them into plant tissue, therefore preventing the accumulation of harmful ammonia, nitrites and nitrates, and stabilizes the pH. By maintaining a clean environment, the EcoSystem Filtration Method keeps fish healthy and their colors vibrant. Furthermore, we have discovered through our research, that our filtration system helps prevent and even cures lateral line disease. See Freddy's Odyssey.
The Ecosystem Filtration System requires minimal maintenance, and is a cost-effective way for you to keep a flourishing tank of fish and inverts. We invite you to learn more about the Ecosystem Filtration Method.
A Breakthrough for Hobbyists
No More Guessing
No Protein Skimmer Required
No More Balancing of Chemicals
Reef and Fish Keeping Made Simple
Discus and Tropical Fish Keeping Made Simple
A Simple and Natural Approach to Aquarium Filtration
Achieve Professional Results With No Prior Experience
Prevents and Reverses Head and Lateral Line Erosion (HLLE)
You Can Do It