The Light at the End of the Tunnel

Introduction

Many new to the hobby find the idea of integrating water lilies and other plants with their Koi irresistible. The combination certainly makes for a beautiful display of color and texture. However, in most cases, plants and fish need different environments to thrive. Lilies, for example, require a shallow depth whereas Koi should have a much deeper pond. Shallow water gardens are prone to more algae production and the leaves and flowers dropping off the plants add additional organic loading to the pond. This additional loading degrades the environment for the Koi, and requires more effort by the owner to maintain. Further, Koi tend not to develop to their best potential (conformation and size), and are at increased risk of predators in these shallow ponds.

Case Study: Hanako Koi Ponds Renovation

A recent renovation by pond builder Hanako Koi Ponds demonstrates a way to retain the aesthetic value of both a water garden and Koi pond. When the owner of this pond experienced all of the above-mentioned problems, the solution was to divide the existing pond into two separate bodies of water, with dedicated systems for each. The original pond was concrete and was only about 2 ft. deep at its deepest point. Its bottom was “V” shaped. To utilize the existing waterfalls and stream required a bit of “surgery.” After relocating the Koi to holding tanks, the contractor cut the concrete along the upper edge of the pond and removed the concrete basin leaving only the waterfall and its concrete base. They then excavated the main portion of what would be the Koi pond and hand shaped down to an 8 ½ ft. depth. At the selected point in the original pond, the contractor built a new dividing wall to separate the two bodies of water using concrete-filled cinder blocks and rebar. This gave the “Koi pond” side a final volume of 9,800 gallons.

Construction Details

Once the block, rebar, and concrete filter pit area was constructed, the contractor installed the equipment supplied by Mystic Koi & Water Gardens of Upland, CA. Two 4-inch return aerating Rhino bottom drains, six 2-inch TPR’s, a 3-inch return (to which all six TPR’s could be diverted to create a massive current for the Koi to play in), and a skimmer were all installed. Once a web of rebar was in place, the contractor created the new shell from gunite and polyurea. The water is gravity fed from the main drains to two Nexus 300 filters and returns via two Performance Pro Cascade 1/8 HP pumps. Water drawn through the skimmer feeds an Ultima II filter and Zap Pure 20 UV light via a Performance Pro Artesian ½ HP pump. An additional ½ HP Performance Pro Artesian supplements the waterfall flow for show. Three Airtech AT – 120 air pumps supply all the air for the entire system.

Gunite and polyurea also form the surface on the water garden side. It is equipped with a Tetra 3-inch bottom drain and skimmer. The water flows to an Ultima II filter and 120-watt Aqua Ultraviolet UV, reused from the original build.