One of the best ways to keep algae under control in your water garden is to install a U/V clarifier, which has a germicidal, ultraviolet bulb in it. When the water passes through the chamber and past the bulb, it irradiates the algae, killing it. This keeps your water clear. There are also some good chemicals available. One is called Algae Fix, which is an algaecide that’s safe for plants and fish. Accu-Clear is a coagulant, which clumps single celled algae particles together so that they become large enough for your filter to catch them.
Want to keep algae out? Change your filter pads regularly. Make sure your water is flowing through the pads and not over them. As for fish food, the more waste you have in your pond, the greater chance you’ll have for algae to develop. Feed your fish twice a day, with no more than they can eat in three minutes. Barley straw is a great product to control algae. Float it in the water. In conjunction with oxygen and sunlight it creates a humic acid, which breaks down the barley straw and creates a form of hydrogen peroxide, released slowly in the water, controlling algae admirably. Barley straw comes in pellet form, small bales, and liquid form as well.
If your pond is in full sun, you will need to have lots of vegetation cover, if you want to fight off algae. This works in two ways: Lily pads will shade the water from the sun, cutting down on algae growth and marginal plants with root systems in the water will absorb nutrients, starving the algae out. Plants are a very big anti-algae asset, along with not overstocking on your fish.
While we’re on the subject of stocking fish, the rule of thumb is one goldfish for every 30 gallons of pond water volume and one koi for every 250 gallons.
There’s also a blue dye you can put in your pond water, which absorbs the ultraviolet rays of the sun, starving out the algae. The only downside to this is that it turns the water blue and makes it a little more difficult to see your fish.
Follow these simple tips and you’ll have an algae-free pond all season long!