Algae | How to handle it and remove it from your pond
Removing algae from your pond can be challenging. Here are some important steps to look at to be sure you are removing each variable to help decrease algae growth.
What is algae?
Algae is a plant that does not have a defined root system that feeds off the debris or fish waste built up in the pond. Most algae that are seen in your pond are a single cell type of algae.
Algae can grow and thrive from a few different sources. Eliminating or controlling each of these potential sources will help determine what is feeding your algae growth.
- Excess waste/organic debris
- Too many fish for the size of the pond
- Lack of maintenance
- Excess lighting
-
Bacteria in the water that is not established well enough
Algae and bacteria both use the same food source to grow. Increasing the bacteria and reducing the waste in the water will allow the bacteria to compete against the algae for the same food source.
How to decrease and eliminate algae.
First, you’ll want to determine the number of fish you have and the volume of water. You may have an overstocked pond. For ponds, the rule of thumb for fish per volume of water is each koi fish under 8 inches requires 100-150 gallons and each adult goldfish requires 30 gallons of water. Once you know that overstocking isn’t an issue, here are some additional tips below:
- Water exchanges will help dilute the fish waste/organic debris because the pond is a closed system of water and cannot do it naturally.
- Reduce light – add a shade cloth if applicable. Reducing or removing light can slow algae’s photosynthesis process down and it will in turn grow at a decreased rate.
- Add bacteria to the pond - Bacteria will eat the algae’s food source. The more bacteria the better! Use API® POND-ZYME™ SLUDGE DESTROYER™ bacterial cleaner or API POND ECOFIX™ SLUDGE DESTROYER™ bacterial cleaner.
- Use an algaecide like API ALGAEFIX™ algae control. API ALGAEFIX™ algae control will kill green water algae and string algae.
- Live plants – plants will help reduce the fish waste and organic debris in the water column making it unavailable for algae to use.
- Reduce the number of fish if you calculated that you have too many.
Keeping notes of your most recent pond maintenance will allow you to determine if you need to increase the care of the pond.
What does an algaecide do to algae?
Algaecides like API ALGAEFIX™ algae control disrupts the polarity of the algae cellular wall, impacting the algae’s ability to transport molecules across its membrane and ultimately leading to lyse of the cell.
What to look for when using an algaecide (all other steps should be reviewed prior to using an algaecide).
- Checking the water parameters of your pond weekly with an API Test kit will allow you to determine if other maintenance is required prior to adding an algaecide.
- Confirm pond volume so the water can be dosed appropriately.
- Make sure aeration is appropriate for the volume of water and number of fish.
- In a pond, aeration is water movement like a fountain, air stone or waterfall that increases dissolved oxygen to the water.
- It’s recommended to add more aeration in the warmer months for ponds. Why?
- Algae is a plant, and plants produce oxygen through the process of photosynthesis. If there is a lot of algae in the pond, it would create dissolved oxygen in the water column. By removing algae, it is removing a source of dissolved oxygen for the fish. Warmer weather will increase the speed of which dissolved oxygen moves through the water column. Most algaecides will have a warm weather aeration caution. Always add additional aeration to the pond during the spring and summer especially if you have decided to use an algaecide.
- It’s recommended to add more aeration in the warmer months for ponds. Why?
- In a pond, aeration is water movement like a fountain, air stone or waterfall that increases dissolved oxygen to the water.
Whenever using an algaecide, is it very important to read labels thoroughly, dose appropriately and to monitor the filters, aeration and fish behavior. If you suspect something is wrong, we recommend performing a partial water exchange and to use API POND STRESS COAT™ water conditioner. Our API Technical Support team is always here to help if you have any additional questions or concerns with how to get rid of algae.
NOTE: All recommendations are for ponds that are synthetically lined.