Green Pond Water: Reasons And Remedies- Aquaristland

Does your pond water look like green pea soup? That’s what is called “Green Pond Water.” And unable to see your pond fish because of green water is one of the most irritating.

So, why your pond water became green? Or, what causes green pond water?

Pond water becomes green because of single-celled plant organisms (free-floating bacteria/algae), also known as algae. When this organism or algae thrives or grows at an exponential level, your pond water turns green. The nutrients imbalance (high amount of phosphate and nitrate level), excess light, and the absence of enough oxygen providing plants in the pond water boost this alga to bloom. 

Reasons Behind the Green Pond Water

As we’ve mentioned, nutrient imbalance plays a major role in green pond water. Let’s see what manipulates nitrates and phosphate levels-

Bottom Level Organic Matters:

sludge and muck in the bottom layer include- dead leaves, plants, animals, fish waste, and grass clippings decompose and release the nutrition, which boosts the green water algae.

Too Many Fish in the Pond:

In some cases, your pond may have more fish than the capacity. Koi and Goldfish two most common pond fish. 5-6 Koi fish can grow moderately large, create considerable waste, and make your pond water dirty.

Although the Goldfish won’t grow as big as Koi, but they do spawn several times a year and increase the number rapidly.

Lack of Plants:

Another reason for pond water to be green is the absence of enough aquatic plants. Plants produce oxygen and consume the same nutrition as algae. So, the algae have to compete for the food to grow, which won’t be enough for them to thrive.

Excess Light Exposure:

Too much sunlight exposure also provides nutrition to algae to grow. In the summer, this alga could bloom, and pond water turns green.

How to Control or Clean the Green Pond Water (Algae) Naturally:

The best and optimum procedure for any problem should be the natural solution. As long as the natural methods work, you shouldn’t go for the other ways. It’ll help your pond ecosystem in optimal condition. So, how do you clear your green pond water naturally

Decrease the Fish Stock:

Fish waste is one of the primary food sources of algae. So, check the number of fish you have in your pond. If your pond is having a recurring green water problem, the fish stock could be the reason behind it.

Remove some fish and give away to your family, friends, or you could transfer some to another location. Move some of them indoor can be a good option.

And prevent yourself from putting more fish into the pond. It’ll help you to fight pond algae naturally.

Clean the Pond and Remove Sludge:

As we’ve mentioned before, muck and sludge are another nutrition source for algae. Keeping them in check can help you to prevent your pond water from turning green. You can use a net or vacuum to remove sludge from the pond.

If you need to drain your pond, read here- How to Drain a Pond

Remove the leaves and other wastage before getting into the bottom. You can use a net to prevent falling the leaves and wastage to fall on your pond water.

Reduce Fish Feeding:

Excess food becomes excellent nourishment for pond algae. And extra food means extra fish waste in the water. Goldfish keep eating as long as the foods are available to them. Some other fish will also continue eating if there’s food in front of them.

So, try not to overfeed your fish. It’ll increase the fish waste in your pond. Consequently, the algae will thrive, and the pond water becomes pea soup.

Introduce Algae Eater:

Some fishes are happy to munch on algae in the water. Introducing those fishes in your pond will help you to prevent algae growth. Fish like – Siamese Fighting Fish, Koi, etc., are pond algae eater.

If you want to read about Pond Algae Eaters: Common and Popular Pond Algae Eaters.

Daphnia is also a great addition to your pond as an algae eater.

Grow Right Aquatic Plants:

Another best to clear your green pond water naturally is to grow aquatic plants. The right clear water plants will fight for the nutrition available in the pond water. So, the algae will starve or couldn’t get enough muscle to bloom.

Other Methods to Impede Green Pond Water/How Do You Get Rid of Green Pond Water?

You can also apply some other methods than those have mentioned in the natural solution section. Let’s see what other options you have to keep your pond water crystal clear:

Provide Some Degree of Shade:

Like other plants, algae love sunshine. They grow faster and stronger under better sunlight. You can provide artificial and temporary shade on your pond. Other than that, your plants also provide some degree of shade.

So, reducing the exposure to the sunlight can help you prevent the pond water from becoming green. Remember not to cover your nature pond entirely.

Use Beneficial Bacteria or Chemical:

The imbalance of nutrients causes the single-celled organisms or algae to thrive in the water. As the pond water has high phosphate and nitrates, proving the algae better environment to grow. This may be caused by the different reasons mentioned earlier in this article.

So, applying some beneficial bacteria (like- Pond Klear) which will consume green algae particles will help you to keep your pond water clean. Those bacteria will also help you to reduce the other waste or organic matter from the pond.

Using chemicals like – algicide and flocculating can help to gain short term solution to your algae problem.

Keep Your Pond Aerated:

Aeration devices increase the pond’s oxygen, which will help the beneficial bacteria grow and breakdown or eliminate green pond water algae. Increasing the oxygen will also minimize the carbon dioxide in the water. And algae do feed on carbon dioxide.

Add Filter:

Adding a filter in your pond can help you from algae growth. But the filter should have the ability to remove the junk from the water and the beneficial bacteria to grow. Without required bacteria, your pond water could be a paradise for algae to thrive. However, filter alone can’t clear your green water problem.

Add Rock:

Rock not only act as an aesthetic look in your pond. They provide great support for growing beneficial bacteria. So, adding some rocks in your pond will help to prevent algae growth. Putting some river rock in the bottom is good for the pond.

Install an Ultraviolet Clarifier:

Ultraviolet light kills free-floating algae in the pond. Use the accurate size UV clarifier for your pond. Also, UV light kills the beneficial bacteria too. So, you need a bog or something to help the beneficial bacteria to grow.

Frequently Asked Questions(F. A. Qs.)

How to Keep Your Pond Water Clean?

  • Oxygenating and Aerating the Water
  • Avoiding Chemicals
  • Avoiding Fertilizer
  • Removing Decaying Matter
  • Not Over-Stocking with Fish
  • Sensible Shade Planting and Keeping A Healthy Garden

Is Green Pond Water Bad?

A free-floating algae outbreak causes green pond water. And algae will eat up all the nutrition in the pond water, which isn’t good for your pond. As the day passes, the pond bottom won’t be visible. Pond habitats will perish if it’s become severe.

Is Green Pond Water Bad For Fish/ Can Green Water Kills Fish?

Green pond water isn’t considered dangerous for fish. Because most fishes will live nicely in it, plants also can easily survive in the green water.  Green water is caused by algae outbreak, and many fish and plants happily live in that environment. Some fishes eat algae gladly.

However, if it’s an algal bloom and becomes a severe outbreak, Fish and other pond habitats will perish and even kill your fish too.

Is Green Water Bad for Koi? 

As you already know, green water is an algae outbreak in your pond. And Koi eat algae. So, if your pond didn’t become entirely wasted like thick pea soup, Koi fish can handle light green water easily.

If you’re interested in what Koi fish eat and what to feed them, read here- What Do Koi Fish Eat

Final Thought

An algae outbreak in your pond causes green pond water. If you want to keep your pond water clean, you must prevent the reasons behind the algae to thrive.

Green water isn’t bad as long as it’s not severe. Just follow our given guidelines; your pond water should soon become crystal clear.

If you’ve some problem regarding this, please feel free to share in the comment section. We’ll be happy to help you with any information you need.

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