They say a picture is worth a thousand words. This one-of-a-kind koi pond, built by DIYer Phuoc "Kevin" Tran, takes a few more, because part of it is in his backyard and part of it is inside his enclosed patio.
A pond he could see from the house
Kevin had kept a water garden pond for more than ten years. His one regret was where he put it: far from the house, where he could not see the fish. So in 2020 he built a new koi pond right up against the house, close enough to watch his koi from the window.
It took him about four months to plan and build, and he told us he almost gave up before he finished. We worked with him on the design and the equipment along the way, and the result is one of the very few indoor/outdoor koi ponds we have seen.
An L-shaped pond, inside and out
The pond is an L shape that holds about 5,000 gallons and wraps both outside and inside Kevin's enclosed patio, so the same koi swim on both sides of the patio wall. Raised walls faced in stacked stone, with a white stone-look coping, frame the water on both sides.
Inside, a clear acrylic panel 1.25 inches thick runs along the front wall as a viewing window, so Kevin can sit at eye level with his koi. If you want a window without the custom acrylic work, take a look at our Pond Portals koi viewing windows.
Two lit spillways
Working back from the outputs, Kevin wanted clean lines for his falls and a way to light up the room with color-changing LEDs. There are two lit acrylic spillways, one in a stacked stone wall inside the patio and one in the wall out in the yard, so at night the falls glow on both sides of the windows. For the falls he chose the Atlantic Water Gardens 36-inch Colorfalls color-changing spillway (CC36).
Eight Aquascape 8-watt color-changing LED spotlights light the water, run from Aquascape's color-changing control hub on a 150-watt transformer with a photocell.
How the water moves
Flow can be tricky in an L-shaped pond, because each leg tends to hold its own dead spot. Kevin's pond uses three tangential pond returns (TPRs) to keep the water turning and push debris toward a 4-inch Aquadyne Rhino II bottom drain with an air diffuser. At the surface, a Savio Standard Skimmerfilter with the 16-inch weir faceplate pulls in floating debris, and a Savio auto fill valve keeps the water level constant.
To keep energy use down and the pump running for years, we chose a Low RPM ArtesianPro 1/3 HP pump. It moves about 7,300 GPH at 3 feet of head, which fit his filtration and UV.
Filtration: drum, beads, then UV
With a viewing window there is nowhere to hide murky water, so Kevin went with high-end filtration in the order we recommend for most bottom-drain ponds:
- A self-cleaning rotary drum filter (a C30 Pro) as the prefilter, to strip solids out of the drain water before they reach the pump.
- An Evolution Aqua K1 MicroBead 36 bead filter for mechanical and biological filtration.
- A 150-watt Matala stainless steel UV with 2-inch unions at the end of the line to keep green water away.
The K1 MicroBead has since been discontinued. For a pond this size today we would look at a GC Tek AlphaNANO bead filter, and for a drum we carry, the SeaSide Aquatics RDFs are a close match. Both are in the plan at the end of this article.
We couldn't be happier with how this pond came out, and we're grateful Kevin let us be part of it. Here is a second look at the finished pond.
Kevin's pond at a glance
- Builder: Phuoc "Kevin" Tran, DIY
- Build time: about four months, in 2020
- Shape: L-shaped, with raised stacked stone walls, part inside an enclosed patio and part outdoors
- Volume: about 5,000 gallons
- Viewing window: clear acrylic, 1.25 inches thick
- Falls: two lit acrylic spillways
- Lighting: eight Aquascape 8-watt color-changing LEDs
- Filtration: bottom drain and skimmer, rotary drum filter, bead filter, 150-watt UV
Materials used in the build
- Atlantic Water Gardens 36-inch Colorfalls color-changing spillway (CC36), with the Colorfalls master control wiring kit (CCCM05)
- 3 tangential pond returns (TPRs)
- Aquadyne Rhino II 4-inch bottom drain with air diffuser
- Savio Standard Skimmerfilter with the 16-inch weir faceplate assembly
- Savio mechanical auto fill valve kit
- ArtesianPro Low RPM 1/3 HP pump
- C30 Pro rotary drum filter (RDF)
- Evolution Aqua K1 MicroBead 36 bead filter (discontinued)
- Matala stainless steel 150-watt UV with 2-inch unions
- 8 Aquascape 8-watt LED color-changing spotlights, with Aquascape's color-changing lighting control hub, a 6-way splitter, a 25-foot 5-outlet extension cable and a 150-watt transformer with photocell
- 2-inch Aquascape flexible PVC pipe
- 1.25-inch clear acrylic viewing window
Plan a pond like Kevin's
We rebuilt a version of Kevin's pond in our Pond Planner at about the same volume: a 14-by-14-foot L, 5 feet deep, with a raised stacked stone wall 2 feet 8 inches high, a 32-by-80-inch viewing window facing the patio, two 36-inch Colorfalls and about 4,900 gallons of water. The planner fills in equipment we carry today, puts the filters and pumps in a stone pump house beside the pond, and lays out the plumbing from the three bottom drains to the returns. Open it in the planner to look around in 2D and 3D, then change anything you like to plan your own.