How to Clear Lake Water

What causes green water and algae in lakes? 

Lakes have a particularly large surface area which leaves them open to the elements and makes it very easy for plant debris to make its way into the water. Over time fallen leaves and twigs sink to the bottom of the lake and start to decompose. As they decompose, they add to a layer of organic matter, or sludge, on the bottom of the pond. This sludge then acts as a food source for algae and green water, leaching out high levels of nutrients into the water. In ornamental ponds with filtration systems, this is less of an issue. The pump and filter can physically remove the sludge and in turn the food source. If left untouched, this sludge can begin to turn anaerobic and over time, produce hydrogen sulphide which can give off a rotten egg smell in water. This gas can pose dangers to wildlife in high enough concentrations. 

Pond Plants 

The same nutrients that feed the green water, blanket weed and duckweed also feed pond plants such as lilies. Consider adding pond plants both in the marginals and in the deeper parts of the lake. Plants such as lilies will help to absorb nutrients and also create a layer of cover on the surface of the lake from the sun. Reducing the amount of UV that enters the lake will reduce the growing conditions for algae and green water. Discover a beginners guide to pond plants here.

Aeration 

As lakes typically have slow-moving or stagnant water, it is very easy for nutrients to collect on the bottom of the lake and begin to build. Adding a simple form of aeration such as a solar fountain can keep the water moving. This will also increase oxygen levels in the lake. 

Bacteria

The most cost-effective treatment for green or murky water in lakes is a bacterial treatment such as Envii Lake Klear. Using a blend of beneficial bacteria, Envii Lake Klear binds together and sinks the particles that cause green water to the bottom of the lake. Once there, they begin to break down the particles and sludge converting them into oxygen and CO2. These are then absorbed by the pond plants. Breaking down and digesting this sludge also prevents harmful hydrogen sulphide from being released into the pond. The bacteria remain present in the water continuing to break down organic waste and keeping water clear. Regular treatments of Envii Lake Klear help to keep water clear and promote thriving ecosystems for wildlife. 

How to clear algae in lakes? 

You will usually find that you either have green/murky water or an algae or weed such as blanket weed or duckweed. This is because the algae and weeds use the same food source as green water and as they are stronger, they are able to outgrow the green water spores and in turn, prevent the water from turning green.  

One common approach when clearing algae from ponds is to physically pull out the algae. Whilst this provides a quick solution, it is also a short-term solution and can compound the problem going forward. Once algae is pulled from the water, it breaks and releases new spores into the water. These spores then grow quicker and more aggressively than their predecessors and in some cases, blanket weed can return within days. 

Whilst algae can be killed and prevented using a bacterial treatment such as Envii Lake Klear, a quicker option is to use a treatment such as Envii Algae Klear Xtra to directly target and kill the algae.