Koi Pond Algae

Koi pond owners often have to fight algae problems in their ponds and while there are a variety of ways one might treat algae, extra care needs to given to those that have fish of any kind including koi fish.

One thing that needs to be kept in mind is any pond that contains fish, must have some form of filtration, and ideally biological filtration, in adequate capacity to help deal with the waste that the fish create. Many water quality problems can come up if a pond is under filtered, or if too many fish end up in the pond for it's size and volume.

It could be said, and most experts agree, that high fish loads end up creating koi pond algae or algae in any small fish pond more than anything else. Fish, and particularly koi, can eat a lot, and they can create a lot of waste. The more fish you have in a pond, and the larger they are, the more influence they might have.

So the first rule is to make sure you don't have too many fish in a pond for it's size. We have a simple fish load calculator you can use to determine if your pond is overstocked.

If you do find your fish are overloaded it would be best to find another home for some of them and to lessen the load on the pond. Many times when this is done, a pond can return to a fairly good condition without much more being done.

Fish, of course, need to eat, but it's best to not overfeed them. Uneaten food can sink to the bottom and raise nutrients in the water as the food breaks down. Ideally you might want to only feed your fish once per day, and no more than they can eat in about five to ten minutes. If you ever see much food going to waste, back off a bit on the feeding amount. You might also want to look for a floating fish food which will give them more time to eat without wasting any food on the bottom.

It's also not a bad idea to add beneficial bacteria for small ponds from time to time, first to help prime up a biological filter, if one is in place, and secondly to help get some active bacteria working in the pond body itself. This can help lower nutrients like phosphates and nitrates that algae might feed on to grow.

If the pond get's a lot of sun exposure it's also useful to add surface or floating plants to help provide some shading, however some koi love to eat plants and may damage them if they are not protected. One useful tool for this is to put plants in floating islands which also provide shading but protect the plants as well.

By taking some of the simple steps noted above, many pond owners have helped to clear their ponds of algae and they've done it safely and without the use of harsh chemicals.