Pond expert Brian Connelly shares his knowledge of koi fish.

Koi are a colorful, entertaining addition to any decorative outdoor pond or water garden. But how much do you really know about these seemingly exotic fish? We spoke with Brian Connelly, co-owner of Phoenix-based CTK Quality Pond Products LLC, which specializes in designing and building “high-end, complex koi ponds for Valley residents” to learn more.

The Amur carp’s origins stem from Japan, where farmers began to breed the fish for color in the 1820s. Similar to purebred dogs or horses, they are hand-selected to reproduce the best size, color and patterns. These characteristics help distinguish one variety of koi from another. Each is available in a Doitsu (scaleless) version and a Ginrin type with sparkling scales.

There is a wide range of koi on the market, but the most desired are the Kohaku (white body with a red pattern), Taishō Sanshoku (white body with black and red markings) and Showa (black body with white and red/orange colorations). Depending on its design and size, a high-quality koi can retail for $3,000 or more.

While koi are typically found in Japanese-style gardens, these aquatic companions have made waves in Arizona, with residents incorporating the fish into their homes in creative ways. For the past 18 years, Connelly and his wife, Annette, have helped their clients with all things koi, such as pond filtration, design, maintenance and the sale of the fish.

Here, Connelly offers insight on these beautiful fish and their prominence in the desert.

Phoenix Home & Garden: How did you get started in the koi business?

Brian Connelly: My father began building ponds in Oklahoma in the early 1980s, so I worked with him. When I was a kid, I played in the creek every single day, and I absolutely loved it. I grew up doing normal jobs, but when I started working for my dad, I realized “This is just like playing in the creek, but you get paid for it.” I was about 20 years old when I went to work for my dad, and in 2000, I moved to Arizona to start my own business.

PHG: Is it common to find koi ponds in the desert?
Connelly: There are tons of koi ponds here. Arizona is great because there really isn’t a cold season. Back in Oklahoma, we wouldn’t work for four months. Most of our customers are retirees who had ponds at their previous homes elsewhere in the country or who went on vacations and saw beautiful koi ponds. Once they build their dream home here, they say “I want a koi pond just like the one that was at that particular hotel or what we had where we came from.”

PHG: What is a typical koi pond like?
Connelly: No two ponds the same, but the filtration system is the same, no matter what the pond looks like. There are two types of ponds: Aquagate ponds have gravel and look very natural. But the gravel is a breeding ground for fish parasites and the ponds get nasty and dirty. Higher-end koi ponds do not have any gravel. Ours are built like a swimming pool with concrete and rebar; they even have liners and fiberglass.

The Carefree home of Carolyn and Jim Halladay is one of the Connelly’s most impressive projects to date, and was featured in our April issue. Click here to read the full story!

PHG: What kind of space do homeowners need to have for a koi pond?

Connelly: The smallest size pond you could have in Arizona holds about 1,000 gallons. This is needed simply because of our heat. We don’t want the water to get too hot. Footprint-wise, this could mean you have 1,000 gallons in a 5-foot-deep area, depending on how big around you want the pool to be. From there, it just goes up. It depends on how elaborate you want to make the pond.

PHG: Why is filtration so important for koi?
Connelly: Filtration is key for any kind of fish because it determines the health of the water. If the water is not healthy, the fish are not going to thrive. I would compare it to us living in a closet without any restroom—if we do so, we are going to get sick. A pond needs to have the ability to clean out all of that waste and other debris in order to maintain the overall health of the fish.

PHG: Where can Valley residents purchase koi fish?
Connelly: There are not too many places that sell koi fish in the Valley. You can find domestic ones at some of the big box pet stores, but we are the only one, that I know of, that sells Japanese koi fish. I bring in all of mine from Japan through California.

PHG: Why are koi so expensive?
Connelly: Each fish is one of a kind. The Japanese koi have bloodlines similar to that of horses and dogs. The price corresponds to the bloodline, patterns and the rarity of that specific type of fish. If there is only one fish with a particular pattern, and if it is near perfect, it is going to be very expensive.

PHG: How homeowners ensure that they are getting healthy fish?
Connelly: You want to find one dealer who is very reputable and who you trust. It is not wise to put a bunch of koi from different locations in the same pond at one. That’s like us getting an airplane—if anyone is sick, that illness is going to spread. Different health issues are typically isolated by different vendors, so when you combine koi that weren’t raised in the same environment, you can end up with really bad problems. You could lose all your fish unless you are really skilled at taking care of koi. You have to be very careful, but the rewards of watching the fish in your backyard is worth the challenge.