Hamilton pond builders

9 ways to clear green pond water successfully

In this blog we are going to cover one of the most common problems pond owners have. How do I clear green pond water up! I want it gone! Not to worry, there are solutions, you can decide what path you want to take.


What causes green pond water?

Nutrient buildup and how it leads to green pond water.

Interventive methods

1. Hydrogen peroxide will clear green pond water.

2. A UV light will clear green pond water fast!

3. Algaecides will clear green pond water!

Natural methods used to clear green pond water.

4. Cleaning out your pond will clear green pond water up.

5. Reducing fish load will naturally clear green pond water.

6. Adding surface area in rocks and filters will help clear green pond water.

7. Adding Bacteria will help clear Green pond water.

8. A unique option to help clear green pond water.

9. Then Last we can add plants to naturally clear green pond water.


What causes green pond water?

Green pond water is cause by algae blooms, they happen due to access nutrient build up in the form of phosphates and nitrates. If you learn what green pond water is, you can be armed with knowledge that will allow you to address the issue head on. Green pond water is almost always caused by algae, a primitive single celled plant that floats in water and acts in the same way all plants do.

They’re a lot like little bastar… whoops I mean little bacteria. lets call them the flowers of the single celled world. Like regular plants algae eats plant food and uses sunlight to continue to live and reproduce. So to clear green pond water we need to clear out the food and or sun these plants eat.

There are a Number of kinds of algae, most pond owners will deal with two. String or hair algae, and green algae. The one most people don’t want to deal with is green algae. it does what is in its name. Turns the water green. String algae is less invasive most of the time showing up on falls and the marginal areas.

String algae is part of a healthy pond, green algae is not! Both can be removed with the techniques below to different extents. We are going to focus mostly on green algae in this blog. But when the method will work on both I will let you know.

get clear pond water

The reason Algae grows can be put simply, to much plant food not enough methods to remove it, causing the algae to grow. However the reasons are a little more complex than that. Like all plants Algae loves to eat nitrates and phosphates and it uses the sun for photosynthesis.

So the solution to the problem comes from eliminating one or all of these sources so that it does not have a chance to dominate. When you do you will clear green pond water up! We are going to cover these methods below but first its important to learn what causes access nutrient build up.

Nutrient buildup and how it leads to green pond water.

So what cause these food sources to be present in a Pond? Well over time organic matter builds up in the pond from lots of different sources. Fallen leaves, fish waist, grass cuttings, and over feeding fish. These are just a few things that enter the pond ecosystem.

As these debris break down they essentially turn into compost. Aerobic bacteria will eat it up and break it down into its basic components just the same way it does in a compost pile. If there is not enough of these bacteria then the access nutrients releases into the water. Once these nutrients build up an algae bloom soon follows.

Clear green pond water up

Important tip! It is worth mentioning that these algae blooms almost always happen after a new pond is built! The plants planted and the bacteria has not had tome to establish itself, algae being what it is will take over as soon as it can. Just be patient and allow nature to take its course.

If you tamper with it to much you can set things back. Its also wise as hard as it is to wait to buy fish, when the algae is gone you know the pond is ready! and if you get them while its green you will only frustrate yourself trying to look for them! in this case Patience will help clear green pond water up!

Now before we go and give green algae a bad name I want to give you a reason to like it as well. Really their not little basta… they are helpful in a way! Did you know the reason algae blooms, is the same reason fish die?

The water is to dirty and so all sorts of things can happen like oxygen levels dropping, or simply the water is so overwhelmed with ammonia for fish to live in. So green algae is a way your pond is telling you there is a balance off that needs to be fixed. I know I’d rather have green water over dead fish. So lets say thanks to nature for giving us such a cool warning system!

Lets get into the meat of it! There are a thousand ways from Sunday to tackle this problem, some natural and some more built around human intervention. I will cover the intervention means first, every option has its pros and cons, none are wrong or right, all have different results that last or are temporary.

If your better talking in person on how to clear green pond water call us anytime, advice is free!

Interventive Methods to Clear Green Pond Water

Hydrogen peroxide will clear green pond water.

Yup that’s right, the stuff your grandma dumped all over your cuts, that made them fizz, and sting,! Yes, that will clear green pond water! It will also not kill your fish if done properly. However I would suggest being very carful, you don’t want to overdose and hurt anyone. Always dump it into an area where it will mix fast.

We recommend getting a 5 gallon bucket to dilute it with water from the pond, then dumping that into the pond. This way you insure it wont reach any fish gills in a concentrated form and burn them.

So there are a number of precautions you need to take. Ill give dosing quantities at the end of the section, be sure to read carefully! How the Peroxide clears green pond water is straight forward. It has anti bacterial properties, that’s why we use it on cuts! Essentially algae is single celled, so when the peroxide touches it it removes its outer protection. Algae does not have what it takes to protect from the effects of the peroxide so it breaks down!

remove pond algae

Once it breaks down it can lead to ammonia spikes in the water because now there is an abundance of food and not enough bacteria to eat it.

This can cause fish die off! So the goal is to only introduce a leveled amount of hydrogen peroxide to not kill off the algae to fast. There are a few ways to do this. First is adding 1/2 cup of 3% hydrogen peroxide in for every 100 gallons. To calculate the gallons in your pond you can use this helpful calculator.

Another way to get peroxide into the water is through barley straw, you can buy bundles of it and as it breaks down it naturally releases Peroxide and in turn kills off algae. However, it tends to have a methane smell to it as well and this can be unpleasant, it also requires a lot of it for larger ponds.

Hydrogen peroxide will eliminate siring algae as well as green algae!

A UV light will clear green pond water fast!

For much the same reason hydrogen peroxide works to kill algae, so does UV light. Being single celled they are venerable to any attack to their outside. The UV light destroys the outside of the cell causing it to die off and then clear green pond water up. These lights will not work on string algae because they are localized, they do not travel through the filter system.

How these light work is that they are placed inline with the waterflow between the skimmer and falls. the water flow by and the UV light penetrates killing the cells. This is great because it will take care of the algae fast and long term. However it has some downsides as well.

First is the cost, the larger the pond the more light you will need. These units can get pricey the more light you need. Then they will need to have bulbs replaced as they break down over time. And also there is the electricity needed to run them adding to the monthly bill.

Second is because they kill algae they also kill beneficial bacteria. Now beneficial bacteria typically lives on surface area and so it wont be effected to much, as its not predominantly floating in the water. However, often you will want to inoculate the pond, add bacteria, to the water.

Often adding this bacteria to the water means putting into the water in liquid or powder form. So if its temporarily suspended in the water you will want to make sure to turn off the light while it gets settled to not kill it!

If used properly UV lights are a great solution to clear green pond water up. Especially for ponds that have limited space where adding more plants and filtration is difficult. They don’t need much space and can solve the problem if the area is tight!

Algaecides will clear green pond water!

The last interventional method to remove algae is to use an Algaecide. There are many kinds on the market, technically our hydrogen peroxide solution is one. Essentially these product do what we have been talking about they remove the nutrients through creating competition for them, or they directly kill the cells themselves.

The downside to these products is often they are temporary. if the root of the problem is not addressed the algae blooms may return. so this will lead us to our natural solutions, witch are often long term or permanent.

If your better talking in person on how to clear green pond water call us anytime, advice is free!

Natural methods used to clear green pond water.

as clean as nature
Get your pond as clean as nature itself!

These natural ways to clear green pond water boil down to one of two things, removing or adding.

Like we talked about, a pond is about creating a balanced eco system, to clear green pond water naturally you will need to either remove a cause of or the food source for the algae.

Or add something that will eat that food source before the algae has a chance to leaving it without a place to dine!

Cleaning out your pond will clear green pond water.

Both regular and yearly cleaning will help reduce the amount of debris that turn to slug that intern lead to algae blooms. If you allow leaves and grass clipping to always drop to the bottom and never clear them out your allowing nutrients to build up that algae love to eat.

So getting in there here and there and making the effort to clear any lose debris out will go a long way to keeping the water clear. you can even stir up the bottom here and there allowing the debris to work there way over to a bottom drain or skimmer. Another option is to point a Jet of water at the bottom of the pond making sure its always directing debris over to the filter areas.

Reducing fish load will naturally clear green pond water.

Yah I know, this one is sad! who really wants to take fish out of their pond right! Chances are you didn’t even get to reading the first sentence! But Ill explain anyways, so fish eat food and poop like al living things. this means your adding organic matter to the water by having them in there, if you put to many in then you tip the balance to far and the poop and food turns into food for algae. so selling a few off will help clear green pond water.

Adding surface area in rocks and filters will help clear green pond water.

happy koi fish in clear water

Why add surface area in the form of rocks and filters? well it adds living space for beneficial bacteria. Yes you can perform a form of biological warfare on algae.

By adding more living space it you create competition for nutrients. removing the food source. As long as this bacteria can live they will always eat up the food before algae has time to bloom!

The fun part about this is you can add to the design of the pond. Put some river stone on the bottom, rocks on the edge, or even a wetland filter on the margin of the pond.

Or you can increase the filer surface area. replace the bio falls with a larger unit, or add another stream or falls somewhere else in the water feature. remember regular doses of beneficial bacteria will keep these surfaces colonized.

Want to chat in person about how to clear you green pond up, we would love to help, advice is free!

Adding Bacteria will help clear Green pond water.

There are some great products on the market that allow you to add bacteria that naturally occurs i n fresh water. In nature water runs down hills and mountains before it enters the streams, along the way it carries beneficial bacteria that helps eats organic debris. By adding this bacteria to the pond you are doing the same as adding surface area, creating more bacteria to compete with algae.

A unique option to help clear green pond water.

Add a shade sale over the pond! I don’t see this recommended very often, but its a great option for a few reasons. First it takes away the much needed sunlight algae wants, most other plants can survive with a but of shade. So adding some will not harm them but aid in algae reduction. A 30-70% shade cloth will work well. It also has a few other bonuses. it prevents birds of prey spotting the pond and diving in.

It adds shade to the pond that you can enjoy as well. One thing a pond loves is staying cool! the warmer the water the less oxygen it has. Keeping the fish safe from full sun and warm water means they will be happy! And so will you!

Then Last we can add plants to naturally clear green pond water.

Important tip! Make sure you remove all the dirt from the roots of the plants you are putting in your pond! Dirt is organic debris, this will essentially add an endless amount of nutrients for algae to eat!

Yup, you can turn what would be green water into flowers! The truth is here I saved the best for last! Because algae is a plant it means pond plants eat what algae eats. Brilliant eh! So if you add more plants you add competition for nutrients, so rather than taking away fish, add plants!

Some plants are better suited than others for the purpose of competing with algae. We will have another blog dedicated to this in more detail. Ill just mention a few ideas here to get you started. make sure to read this though there are a few really important take always!

Water lettuce or water hyacinth are really good for this, they float on the surface of the water blocking out sunlight and their fibrous roots take up nutrients from the water. This removes two sources of life algae require, sun for photosynthesis, and nutrients for food.

These plants are not native to zone 5 though so they have to be bought annually, or kept indoors in the winter. A native solution to Zone 5 is lilies, they put up beautiful flowers and pads and also take up nutrients.

Now this is a vital focus point to keep in mind, look at the roots! What you want to look for is plants that have a tone of new fibrous roots, and will continue to put them out in the future! These feeder roots are the ones that take up nutrients. they will go explore areas of the pond that need then to clean it out.

What you want to do is make sure to pull up extra growth forcing the plant to grow back, new roots are always smaller and more aggressive at taking up nutrients! Established root tend to act like an anchor.

If you ever want to talk in person about this topic, call us any time! We can advise you on your specific situation, our advice is free!

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