Chemicals are not always the ...

Chemicals are not always the preferred solution. Besides the HSE risks for the staff handling these chemicals (loading, transportation, spread etc), you should be able to ensure proper mixing in the pond. Also, more than one chemical substances should be used to kill algae and also remove nutrients that possibly are present in the water (mainly phosphorus). For nitrogen, the only solution would be biological treatment. Also consider that the application frequency should be high to prevent the re-growth of the algae. Hence, use of chemicals is not always an optimum, long-term solution.

What I usually suggest in this cases, is the use of ultrasound producing floating devices to kill the algae and prevent the development of new ones, combined with floating treatment wetlands that will uptake the nutrients present in the water. The combination of these two systems provides an optimum result to maintain good water quality, prevent algae growth, while it is an environmentally friendly solution with minimum costs.