How I Maintain a Virtually Chemical Free Koi Pond, Keep Algae Growth Under Control, and Maintain Clear Water

We have had a Koi Pond of one kind or another for about 10 years, we even had a three quarter of an acre pond put in on our 38 acre tract of land in Centerville Texas, and stocked it with fish, but that’s another story. The first Koi pond we had was one of those black plastic tubs that we put landscape blocks around with a small filter and aerator, we were hooked. We then move on to the in ground type, that you can have professionally put in, which we did, then it wasn’t big enough so we had it enlarged. When we moved the folks who bought our house didn’t want the Koi pond (haven’t a clue what was wrong with them) so we had to remove it, fill it in with dirt and sod. We carried all those rocks to our new home where we had another Koi pond put in one week after we moved in. We prefer the biofall skimmer type pond set up; they just seem to work well for us, so all my information will be geared toward that type of pond.

Where we now live, we have an annual garden tour of homes; our home has been on the tour for the past two years. We have a small side yard, ten feet wide and probably forty feet deep on the side of our “Garden Home”, we love it and have transformed it into our own little oasis. As people have walked through on the tour, one question always seems to come up, when they see our Koi pond, “How hard is it to maintain your pond?” My answer is the same, it really is fairly easy.

We live in North Texas so spring is when we encounter the most algae growth. I like to be as chemical free as possible, in this small of an ecosystem, maintaining a natural balance can be challenging. The string algae can quickly take over a pond if you don’t do something. Hand pulling the large pieces will work well if you stay on top of it, I have also used a brush (toilet bowl scrubber works), if you stay keep at it and don’t let it get ahead of you, it is not too bad. The small Barley bales also are a useful natural method for reducing algae growth. Your Koi, which should all have names, will nibble at the algae, but they alone cannot keep it under control. I like the short green algae that you will find growing on our rocks; I think it gives the pond a more natural look. One of the major factors in the whole algae picture, is how much sun the pond gets. Our first pond was in full sun all day long; I can definitely say I worked harder at keeping the algae under control in that pond than I do in our current pond, which is in shade/part sun. Having a pond with a bio fall, means I have the lava rocks in a mesh bag in the bio fall, this is where your good bacterial growth will be.

I use Microbe Lift PL liquid and I use the Microbe Lift spring/summer packets together, available at http://www.watergarden.com/

I use them as directed on the container, (just a matter of pouring a small amount of the liquid in the skimmer and putting two packets in ever week or two). Our pond water is always clear. If we get a lot of rain, like we did last week, it will turn a tea color for a couple of days, but still be clear. I check my skimmer once a week for debris and clean the net out if there is any debris in it. The filter pad under the net in the skimmer, should be sprayed and cleaned with water, once every month or two, or when it gets full of gunk.

Having aquatic plants in the pond is definitely a key to success. These take out harmful toxins put off by the fish and decaying matter and help keep your water clear. I have a couple of plants in my biofall, two water lilies in the deepest part of my pond (also gets the most sun), some dwarf cannas along the margins and a couple of other marginal plants. It is best not to plant your plants directly among the rocks or on the bottom of the pond (however I have, but its probably not a good idea). There is a good chance the roots will grow between the rocks and cause them to become loose and perhaps fall off. It is better to keep plants in pond planters that allow the roots to grow out, but keeps the plant growth manageable.

I think the key to a chemical free Koi pond maintenance, for me, is to be consistent in keeping up with the good bacterial growth, make sure I have healthy plants in the pond, and stay on top of the string algae. We enjoy our pond so much, it is a beautiful addition to our home and we are continually learning better ways to maintain it.  We welcome any thoughts or suggestions you might have on maintaining a chemical free Koi pond.