Lake,
Pond clarity does not tell you much about the need to fertilize, poor clarity may be due to suspended dirt, clay, etc.
There is a very interesting article on pond fertilization in the May June 2005 (latest with fantastic sunset..) issue of Pond Boss.... It suggests you actually determine which of the three nutrients your pond needs by setting up jars of pond water and adding one or a combination of the Nitrogen, Phosphorus, and Carbon components. It also mentions that when the current limiting or lacking nutrient is supplied, another may become the limiting factor.
I would think setting these jars up would be best done next to the pond.
I am sure there will be a lot of buzz on this site about this simple but ingenious concept and look forward to reading the input. I always though in NPK as fertilizer, does anyone out there know about the Carbon? What form would be best? Urea? Organic xxxx?
