I have recently installed a 1/3 hp Gast Air Pump (~3CFM to 2 airstones) in my pond running 24/7 for the last 6 weeks. The water is just as green (if not greener) than when I started. How long should it take before I see the water becoming clearer?
The pond is 1 acre, 150ft x 350ft, 6ft deep for about 1/2 acre, 20ft at the deepest point (average ~10ft). It is fed by a creek that runs about 400 yds from a spring and flows at 100 gal/min (June), likely 300-400 gal/min during spring melt. The flow is across the width of the pond from the creek to a top-draw spillway. In spring and fall there are strong winds that blow the length of the pond.
There is no fertilizer nearby, however, cows drink from the creek about 2 days/year. Sago pondweed grows thick in about 20% of the area. Cattails grow at one end and where the creek enters.
There are lots of frogs in the spring, minnows, a muskrat, and a great blue heron frequents the pond. I have seen crayfish parts in the heron's droppings--so I assume that the pond sustains lots of life.
The problem is the water is very green--you can only see down about 18 inches.
I installed a Koenders windmill last summer but after a few months' operation, I felt that it was not nearly enough aeration for my needs. Also, the winds are light in the summer months.
The Gast air pump is definitely mixing the layers as I can feel the colder water much closer to the surface. I measured the dissolved oxygen on Sept 7 at 5.5 ppm at a depth of 6 feet.
I was expecting that the aeration would stimulate the aerobic bacteria and the water would be much clearer by now. I would appreciate it if someone could let me know what kind of results I can expect and how quickly I can expect them. Also, should I run the air pump through the winter?
