Discuss – Generally, it’s best to not have submerged plants in large pots, when also keeping KOI. The ideal KOI pond is much deeper than the average water garden, so the necessity for plants to help with water quality and shade is reduced.

With the arrival of spring and summer, that once clear and picture perfect pond is now turning a soupy shade of green. It makes viewing fish nearly impossible and takes a lot of fun out of owning a pond or water garden.

It’s a common problem for a lot of pond owners.

What your looking at is actually very small, nearly microscopic size plants called algae. When all of these little critters group together and get so dense they can literally shade the water and turn it into what appears to be a solid green mass.

Now let’s be clear on this. We’re not talking about a light tint of green in the water, which is actually a really good sign. We’re talking about water that is so green that you can’t see an inch or two under the surface!

For the most part, the biggest problem with planktonic algae is really the view and the disappointment of the pond owner. Fish generally can tolerate green water ok, although even they have limits.

The good news is, that even though green water can be a challenge to treat, there are options and solutions. Since what we’re really dealing with his is algae…we want to take a standard approach to dealing with any algae problem.

First of all, be sure to try to identify the support or nutrient source that is supporting this algae growth. Do you have too many fish in the pond for it’s size? A good rule of thumb for this is 1 inch of fish for every 10 gallons of water in the pond. Any more than this and you might be overstocked.

Discuss – A Koi pond is also much larger than a water garden because Koi can grow to be very large in size, some growing to be the size of large trout or catfish. It is recommended that a Koi pond be large enough to hold at least a thousand gallons of water in order to keep the fish healthy.

When fish are overstocked, they produce more waste material than plants and naturally occuring bacteria can keep up with. When this happens, there is a large excess of nutrients in the water which fosters aggressive plant growth…like algae.

Nutrients can also come from decaying matter that may fall into or lie at the bottom of the pond. Like a compost pile for your garden, this decaying matter simply adds more nutrients into the water, which is something you don’t want or need if you already have algae.

Finally, be sure to check for run off into the pond. Most homeowners work really hard to make their lawns and landscapes look really nice. If your adding fertilizer to your lawn or anywhere around the pond, there’s a good chance that some of it can runoff into the water….thereby adding more nutrients to the water.

So, your first objective to combat green water is to try and reduce these nutrient influences.

Discuss – Including an assortment of plants inside the fish pond, and planting it around the edges will help manage and absorb the nutrients in the fish pond. Some water plants will also help to control the presence of algae.

If you do that and still have an algae problem, the next thing to consider is adding a benefical bacteria and enzyme product to the pond, or adding more plants to help control or balance out some of the nutrients. In most cases, using one or the other, or a combination of both will help quite a bit.

And here’s a final word for caution. If you have fish in the pond, I’d strongly advise against using any type of algaecide product. It’s very hard to treat green water with an algaecide in my opinion without doing some harm to fish. Many pond owners have written to experess their dismay of misapplying a copper based aglaecide and losing all of their fish in a very short time.

Try the natural and progressive options first and if need be, contact a local pond professional to help get your pond back into balance in the safest way possible.

Mark Washburn is an experienced pond management specialists with an emphasis in algae control for
commercial pond applications. Learn more about pond algae and pond care at the Algae Solution website.

Build An Easy Koi Fish Pond. Easy To Build Backyard Koi Fish Pond With Full Illustrations, eBook(R) & Bonus.

Algae control in ponds is fairly straightforward. If we ignore the initial spring burst of green water that tells us the pond is coming alive, we make the first good step.

However if the green persists, it tells us there is an imbalance in the pond ecology. The solution to that is to fix the imbalance. While some pond keepers would have you chuck in some chemicals, the reality is these are merely band-aids and won’t “solve” the problem, they’ll only mask it. If you want to solve the problem consider the sources of the problem.

Discuss – Outline the edges with rock. One should be careful when selecting the rocks that will line the edges of the pond.

Many ponds have too many fish in them. At one inch of fish per one square foot of pond surface, you can either have three big ones at 10-inch length or 30 little ones at one-inch length. (note that 3 ten-inch fish will likely give you 100 one-inch fish every year) If you have a greatere fish population than this, understand two things are happening. The first is the pool ecology is being upset because of too high a level of fish excreted waste and high fish populations are likely eating the oxygenating plants that deal with this excretion waste material. The real solution is to lower the fish population. I note if you have fish and are feeding them, the other recommendation is to stop feeding or to drastically reduce your feeding. Excess food creates excess waste which in turn creates green pond water.

The second solution is to increase the oxygenating plant level. A rule of thumb for doing this is to add one bunch (10 stems or so) of a floating oxygenator plant such anacharis for every 3 square feet of pond surface. Reducing the fish population and adding the oxygenators will clean up the algae in few days. If you add oxygenators without reducing the fish population, the fish will likely eat the plants and the green pond water will not go away.

Discuss – The poor Koi keeper is left wondering what happened. He then proceeds the way of many before him, with a shovel, lots of sand and a determination to fill in what was once a treasured feature of his garden, his Koi pond.

Understand there is not magic bullet here. You have to get that ecology in balance and the way to do that is to follow a few simple rules to control fish and plant populations. The two thumb rules above will solve most algae problems.

Doug Green, award winning garden author with 7 books published, answers gardening questions in his free newsletter at http://www.water-gardens-information.com