All you need to dig a Koi pond is a strong back and a good shovel. At least that was what I believed when I began digging in my Oregon home backyard one fine spring day. Actually, it turned out okay, but I was lucky. Before you begin digging, there are several things you need to consider.
Having a Koi pond is one of the most popular backyard additions in the world. Koi are beautiful fish that are great fun to watch. You can dig a “fish” or “garden” pond in your backyard, but if you want a Koi pond, you will need to do some proper planning.
Koi Need A Big Pond
When it comes to koi pond size, big is better. Good quality koi fish can grow up to 36 inches long—a fish that big needs much more living space than your average pond goldfish. Not to knock pond goldfish. I stocked my pond with a few bright orange “pond comets,” and they added a lot to the fish population’s looks.
There are several “rules of thumb” for how much water a Koi needs. When they are small, you can safely have much more fish in your pond than you safely can when your Koi mature. And getting your koi to the maximum size will soon become your goal.
To avoid getting out your slide rule (anyone still has one of those) and a protractor, I suggest just counting on needing 1,000 gallons for each mature Koi you plan to add. If you plan on 3 mature Koi, you will need a 3,000-gallon tank. This is the kind of math I can still do.
So how big is a 3,000-gallon pond? If we assume, for the sake of argument, that your pond is square and it will be 3 ft deep (probably the minimum it should be), you will need to dig a hole approximately 12 x 12 feet.
Of course, your pond will probably not be square and is likely to vary in depth, so calculating how many gallons it will hold can be tricky. One suggestion, not to be taken too seriously, is to fill up a 5-gallon bucket 600 times and then stop digging.
The pond I built was only about 1,500 gallons capacity, but it was large enough for a few small Koi, and I was happy with how great it looked once it was finished.
Where To Dig Your Koi Pond
Where you dig your property will dictate your Koi pond. Unless you have a huge estate or several acres, your backyard will probably have one or two possible sites that will work.
If you can, choose a site that you can see from inside your home. No many things can beat watching you Koi swim lazily about the pond while you are enjoying a nice hot cup of coffee at the breakfast table.
Don’t dig too close to trees, or you will constantly be scooping out leaves. The same goes for shrubs or any plant growth that sheds. Your pond should get some sunlight because you will want to grow some plants around and in your pond.
Test the ground before you start digging to see what kind of problems you might encounter. In some places, like the backyard I had in Austin, Texas, is a solid rock just about 2 feet down. I had a swimming pool built, and pounding through that rock took the contractor a long time and lifted many extra dollars from my wallet.
If the ground is relatively soft with no big rocks to contend with, you can dig the pond with your own shovel. It depends on how much time you are willing to take and the condition of your back. Hard work, to be sure, but hard work is good for you.
If you have wide enough access to your site, you can rent digging equipment, such as a backhoe. They are available from places such as Home Depot.
When you start digging up your backyard, you will need to find a place for the dirt you remove. I used it to build a small mound next to the pond and put it in a small waterfall. The sound of that waterfall was delightful and a great way to enjoy the backyard while cooking on the grill or just having a cool glass of beer.
How Much Does A Koi Pond Cost
A popular description of a boat is that it is a hole in the water you keep throwing money. And a hole in your backyard can cost money, too. Your cost will be reduced if you can do most of the work yourself. However, there are some things you will have to buy.
You will need a liner, pumps, filters, and cleaning tools. Maybe some landscaping supplies such as bricks, rocks, and cement. And after the pond is built, you will need fish and fish food. Yes, you will be throwing money into that hole in your backyard.
Cost, of course, will vary with the size of the pond and who does the building. Even if you do all the work yourself, you will be hard-pressed to get by on less than several hundred dollars. Is it worth the cost? It was for me!