Green pond water is caused by a type of single celled free floating algae. It is one of the most common problems that people have in their pond and can sometimes be very difficult to control. By following the directions in our Controlling Algae In The Pond page, you should be able to remedy this situation by creating biologically balanced ecosystem. For a list of the best plants to help clear your water visit our Clear Water Pond Plants page.
However, sometimes this algae has a way of continuously clouding a pond even though all the usual criteria for maintaining clear water are met. This could be from a number of things, such as a build up of organic matter in the pond, a heavy fish load or even your water source.
Green pond water can be reduced by cleaning the detritus (debris) from the bottom of your pond with a long handled net or a Pond Vacuum. This is usually done in the spring, and again in the fall after the leaves have fallen from the trees. A new trend that is becoming very popular with pond enthusiasts is to add a Pond Skimmer with an optional bottom drain. This eliminates the need to clean the bottom of your pond because it does it automatically by skimming leaves and debris from the surface of the pond before they sink to the bottom. It also makes filter and pump maintenance mush easier. Another way to reduce the organic matter is to add beneficial bacteria such as Microbe Lift PL in combination with a Sludge Reducer. These beneficial bacteria help to ‘seed’ your biofilter and also consume the ‘sludge’ at the bottom of the pond.
Heavy fish loads or large numbers of pond fish contribute to green pond water because fish waste is broken down by beneficial bacteria through a series of steps into nitrate, which is food for plants and algae. Even if you have a lot of plants in your pond consuming the nitrates and you have too many fish, there will be algae. Reducing the number of fish you have will help to achieve a natural balance.
Some water sources, municipal or well water, have high phosphates. Phosphates also contribute to algae growth as it is one of the main nutrients that plants require to grow. There are different of brands of phosphate removers on the market, but in a medium to large pond they become quite expensive because they need to be replaced frequently.
If you have tried almost everything and still have a green pond, don’t fear, there are still a couple solutions left. First is D-Solv 9. This is an algaecide that not only clears green pond water, but it also eliminates string algae. D-Solv 9 is very concentrated, a 16 oz bottle will treat 9600 gallons of water. If you have a large pond, a 1 gallon bottle is also available that treats 76,800 gallons! It sometimes works with just one treatment, but sometimes take 2 to 4 treatments depending on the conditions in the pond. Next, an Ultraviolet (UV) Light. We carry many brands of UV Clarifiers that will suit your pond. If all else fails, these are sure to work. If you purchase a UV light that is correctly matched to the size of your pond and have the correct water flow passing through it, you will have clear water within two weeks. Guaranteed!