One reason for unclear pond water is algae blooms, which may appear as pea-green soup or filamentous mats that float to the surface of the water. Algae blooms develop when there is an excessive amount of nutrients (such as phosphate and nitrate) in the presence of sunlight. These nutrients come from tap water, rain runoff, fish waste, and debris, fertilizer runoff etc. Previously all algaecides were non-selective and killed or damaged most plants in the pond along with the algae.

PondCare AlgaeFix is the number one solution for a quick fix without killing anything that you want to keep. However, establishing a self-sustaining pond ecosystem is the next order of business in controlling algae for the long run. Rocks and gravel provide the perfect substrate for colonizing bacteria, which eats nutrients that feed algae and helps to keep water clearer. Plants remove nutrients from the water for their own nourishment, which helps to deprive those nutrients from unwanted algae. Algaefix for Ponds will leave them healthy to do their job. Broad-leafed floating plants such as lilies shade the pond. Algae thrives in sunlight, so adding lots of lilies to the surface will deprive the algae of its sunlight. Fish eat insects and, in turn, feed the plants. Mechanical filtration traps debris. Biological filtration counteracts algae-feeding nutrients.

Recirculating pumps add oxygen to the water and allow gasses to escape. Oxygen feeds the fish and the bacteria which feed the plants and starve the algae. There are also some products such as Algae Blocker which tints the water and acts as a type of light filter blocking sunlight as it passes into the water depths, thus depriving the algae of one of its most important needs.

As a side note, Rocky Mountain Pine Beetles are killing the trees along the Rocky Mountain chain. There is a pheromone finally called verbenone that will help reduce the damage. You might want to take a look at it.