Green water in Koi ponds or water features in your garden never look good. It is defiantly not the effect you wanted or expected when building or buying a water feature or pond. Thankfully there are solutions to help keep algae under control. With out these helpful products you are bound to experience green water in your pond at some stage.
Algae comes in different forms, you get filamentous or blanket weed algae. This type of algae loves to grow on your waterfalls, rocks and walls of the pond. This algae often looks like strings and it can get out of control that it will clog pumps and small waterways.
Another form of algae is when it floats on the surface of the pond and one of the worst is when the pond is pea green and you cannot see your Koi or even the bottom of your pond.
Algae are simple chlorophyll containing plants that use carbon dioxide, sunlight, water and minerals. In Koi ponds you defiantly have lots of minerals available for algae e.g.: Nitrates. However algae growth tends to be determined by the amount of phosphate and potassium and not so much as sulphur and other trace elements.
Algae can also be worse at different times of the year. In spring when the water is starting to warm up the growth of algae seems to be high. If your Koi spawn it can also cause your pond to go green. In the winter, the algae seem to be at its lowest, due to the cooler water temperatures and algae growth slows down.
The solutions to green water are to use a good-sized ultra violet system. This u.v system will help to kill the phytoplankton that actually passes through the unit. The u.v system can only kill the algae that pass over the light and each system has a maximum flow rate of water that can pass over the system. If this maximum flow rate is exceeded then the pond will not clear and will remain green.
Unfortunatly the filamentous algae are not killed by the u.v system and an alga side is used for this type of algae. Different products that help control filamentous algae are: Pond clear, Tetra Algo Fin and Bali straw extract. Please becareful when using any product in your pond with fish or plants. The does on the instructions must be adhered to strictly. If overdosing occurs it can lead to gasping fish and may even harm them.