Koi Care Basics Blog

So you thought you didn’t need to worry about winter koi pond algae? Well, think again!

Algae is able to grow both in and under ice. It flourishes until plants begin competing with it for nutrients again in the spring.

Plants use nutrients and compete with algae. They are higher up on the food chain than algae, so they beat them out in the competition.

In my opinion this is possibly THE best reason to have koi pond plants, although there are many other benefits as well.

In fact, it is suggested that plants should cover 70% of the pond’s surface during the growing season.

One way to discourage algae growth in the winter is to have as many plants as you can find that will also grow in the ice. Two of these are pennywort and watercress.

Both fish and tadpoles eat algae. UV lights, algaecides and bentonite are also methods of koi pond algae control. There is no magic bullet.

It may take a combination of all of the above to get your algae under control. UV is expensive and algaecide can upset the balance and even harm or kill your koi.

Both plants and bentonite work with the natural chemistry and ecosystem of your pond.

If you are experiencing bad algae problems one good solution is to go to the grocery store and buy several clumps of watercress (with the roots on), bring it home and throw it in your pond.

And of course pennywort. If you can find it, buy a large bunch and toss it in the pond.

Both watercress and pennywort are readily available, suck up nutrients quickly and help starve both summer and winter koi pond algae!

When you are deciding about the placement of your Koi pond there are several things to consider.

First, koi ponds do better in a shaded or partially shaded spot than in full sun.

You can place a Koi pond in full sun, but a shadier area will  slow algae growth considerably and helps prevent the water from becoming too hot during the warm summer months.

If you build your pond in a sunny location you might want to consider putting up an arbor or awning to provide your pond with some shade.

Shade also helps with protecting your Koi from predators…it gives them a place to hide. And, believe it or not, Koi can get sunburned so having some shade gives them a place to go to keep out of the direct sunlight!

Leaves from trees near the pond, with the exception of pines, shouldn’t cause problems  if your pond is well designed.  Pine needles can create quite a mess as they can make their way through skimmers and leaf baskets and clog up your pump.

Once you have picked a spot and decided on a shape for your pond you can use a garden hose or rope to outline it’s size and shape.  This will give you some idea of  how the pond will look.

Keep in mind that your new Koi pond will probably be the central feature of your landscaping. Once you have the general outline shape of the pond established you can get a approximate idea of how many gallons it would be by multiplying the average length by the average width by the average depth by 7.5 gallons per cubic foot.

You’ll still have quite a few decisions to make but you’ll have a good starting point!

Happy pond designing!

Alan Deacon
KoiCareBasics.com