pondslave,
In the first year of my new pond, I also had the brown "scum" which in my case and in all probability in your case is algae.
In succeeding years, the algae was always the green regular scum variety. I've often wondered if algae takes on the color of the water that its in...brown ponds in first year, brown algae. May be just coincidental. If one of the plant pros such as Kelly knows about this it would be interesting.
At any rate, it is usually easily treated with something like Cutrine plus liquid and/or granules. Lots of posts to read on treating algae...just do a search and read away. You may even find one or two that recommends Tilapia, which I happen to do. They eat algae in copious amounts and turn around and feed your LMB the algae in the form of numerous offspring. Its a system I like very much, very much indeed.
