How to Maintain a Clean Pond

Remember a few months ago when we wrote about building a pond, and how lovely and Zen it can be?

Clear water before adding plants or fish.

This is a Zen Pond.
This is NOT a Zen Pond.

Well, a pond with dirty water is definitely not Zen. We want your pond to be Zen all the time, so here are some tips on dealing with a water feature where the water isn’t exactly crystal clear.

First, you need to remember, if your pond is new, you need to give it some time to clear on its own. Your pond is its own complete eco-system with fish and plants and microorganisms. This aquatic world needs time to settle and sometimes it can be a few months before the water in a brand-new pond becomes clear.

Ponds, like pools, require maintenance like aeration and cleaning. However, you might find that from time to time the water might not be as clear and shimmering as it should be. There are several reasons this might be happening and we have some tips to help you determine what is going on and how to fix it.

Testing for the problem could not be simpler. Let’s just call it the “jar test,” because all you need for this test is — you guessed it — a jar.

Fill the jar with water from your pond and leave it to sit some place dark-ish for 24 hours.

This basically creates your pond in a jar and so whatever is happening in your pond will happen in the jar. At the end of the 24-hour period check the jar and note the color of the water. Here’s what it will tell you:


Green water means you’ve got a problem with algae. Planktonic algae are floating, microscopic plants that color pond water green, blue-green, sometimes brown or variations in between. This is the source of algae blooms and so if you see green or some variation, you know that your jar is telling you to treat for algae.

This water is looking a bit brackish and green.

If you need to get rid of algae very quickly then a chemical treatment is your best option. The type of chemical you use depends on the type of algae you have. Liquid chemicals work best on planktonic algae but if you have string or filament algae then a granular treatment generally works best.

Chemical treatments are fast, but don’t prevent regrowth. Also, some folks are just chemical adverse. If this is the case, then consider using a pond UV clarifier. This method requires that you consider the size of your pump and UV bulbs must be replaced about once a year. Otherwise, this is a good ongoing method for keeping your pond water clear.

Copper ionizers release copper ions into the water which cuts down on string algae growth. This method requires some plumbing work for a new pond build or a drop-in model can be added to an existing pond’s skimmer.

And then there is barley. Barley is an excellent natural solution for maintaining a clean and clear pond. Of course, it is safe for the fish and any other wildlife that might visit. Barley can be used during the winter months when other pond treatments are ineffective. Barley is available in different forms including barley straw extract and barley straw pellets.

Tea-Colored Water

Discolored or tea-colored water means that the tannins from decomposing leaf debris are making the water an icky dirty looking brown. This time the jar is telling you to add a bag of activated carbon to the water.  While the carbon is doing its thing, take the opportunity to remove debris with a net or pond vacuum. This is when regular pond maintenance comes in handy. Regular skimming and covering the pond with pond netting (especially in the autumn months) will keep debris in the water down and the water from turning that ugly rusty brown.


If the water is clear but has a layer of sediment at the bottom, then the jar is saying that you have a profusion of organics in the pond, and those swimming fish are keeping things stirred up and making the water cloudy. The fix for this is just a little more complicated.

Start by moving any large debris from the pond. This is another instance where regular maintenance acts as a good preventative.

Next, perform a partial water change.

Once that is complete, add a water conditioner. Water conditioners are safe for fish, generally dissolve muck and help keep water clear.

Finally add beneficial pond bacteria. These little microbes keep water clear by processing dead organic material.

Back to beautiful!

Who knew a jar could be quite so informative? If, however, you look at the water in your jar and like a Magic 8 Ball, the jar says, “Reply hazy, try again,” then let us know and we’ll see if we can help. Or, check out

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