[gregbickal]

Quote: At this moment I am crunching some numbers and hope to come up with some calculations as to how many kilos of plants it would take to convert nitrogen waste of an average fish in a pond. The sums aren't finished yet but I believe it will be closer to 100's of kilos than 10kg.

How many kilo's are in here Think brushes, thousands of brushes.
Here's some data on Water Hyacinths and Nitrogen removal
The Water-Hyacinth - Dymond
Im not dis-agreeing with the points Scott has made. I do however have a watergarden with koi in it. The plants I have in my pond with the koi are Verigated Sweet Flag, Regular Sweet Flag, and Cattails. All growing in the rock around the edge, no dirt. The water hyacinth in the picture are growing in a 12" deep stream that is 48" wide and has a 8,000gph flow rate. I would say they number in the 2000+