How to clean or remove green water in a pond?

How to remove green water in a pond?

The water in your pool is not translucent, but you have trouble defining its color? To find out if the water in your pond is turning green or brown, filter it using a coffee filter. If your filter is completely green, then apply the solutions in this article to make it clear again. But first, let's take stock of green water in a pond. Is it dangerous for your marine ecosystem?

Is green water dangerous?

In garden ponds, basins and natural swimming pools, the water tends to turn green due to excess algae. However, not all algae are dangerous. One of the best known (and perhaps the most dangerous) is cyanobacteria, or blue algae.

The proliferation of cyanobacteria is more and more frequent in summer because the rivers are low because of the drought. However, these bacteria are harmful to marine animals and create an imbalance called efflorescence. Blue algae tend to suffocate fish, shrimp and frogs in your pond, but they are also dangerous for dogs and humans.

On the contrary, the 7000 species of so-called “ordinary” green algae of the chlorophyte family are harmless. They are even an invaluable source of food for insects, birds, fish, frogs, etc.

Thus, it is difficult to say whether or not green water is dangerous. To find out, we advise you to test the quality of your water. And whatever the result, know that it is essential to remove green water in a pond as soon as it appears. Here are some useful methods...

How do I remove green water from my pond? How do I clarify the water in my garden pond? How to remove green water from a pond? To remove green water from your basin or pond, various solutions exist. Let's go through them together!

1. Use a pond clarifier (UV lamp)

Using a pond clarifier is an extremely effective method of ensuring clear water in your pond. How it works ? It's very simple: in contact with the UV light emitted by the lamp, the microscopic algae decompose. Thus, the pond clarifier prevents your water from becoming greenish.

On average, you will have to wait between 3 days and 3 weeks to find perfectly translucent water. But beware: even if a clarifier gives your pond an aesthetic and clean appearance, it does not filter the water. It is therefore essential to add it upstream of your filtration system.

Good to know: to remove green water from your pool, opt for a power of 3 Watts for 1 cubic meter of water.

2. Invest in a filtration system

Good filtration will allow the water in your pool to renew itself and maintain a suitable oxygen level. Thus, a suitable filtration system is an essential tool! It will prevent water stagnation and ensure the balance of your biotope.

To maintain filtered and oxygenated water, you will need a pump and filter combination. These two installations must remain on 24 hours a day, 7 days a week in order to effectively combat phytoplankton and germs.

3. Introduce aquatic plants

The most natural way to remove green water from your pond is to introduce aquatic plants to compete with algae. Indeed, plants and algae feed on the same thing: nutrients.

Introducing aquatic plants (or adding some to those you already have) will:
- Reduce nutrients and algae growth;
- Release oxygen;
- Shade the pool and regulate its temperature.

4. Vacuum

Yes yes, you read that right: you can use a vacuum cleaner to remove thread algae and a rake for those that float on the surface of the water. First, rake the areas where algae is clumped, as it may clog the vacuum's filter. Then, use the vacuum cleaner to remove the algae suspended in the water.

Our advice: handle your vacuum cleaner with care to prevent it from damaging your aquatic plants.

5. Add barley straw

You may not know this, but barley straw for ponds is a great way to get rid of algae. It is not likely to remove them if there are already some, but it will limit their appearance. This is why it is advisable to add it early in the year before the algae begins to form.

When exposed to sunlight, barley straws release a chemical that stops algae growth. Finally, this method is very economical since it remains effective for 6 months.

Bonus: welcome algae-eating fish to your pond!

To conclude, it is important to remember that certain species of fish are particularly greedy in algae. We can mention the plecos, the loaches, the Molly and the Guppy. For more information on the subject, do not hesitate to consult our article dedicated to algae-eating fish. Finally, consider combining several methods to remove green water from your pond!