Plumbing & Valves

The unglamorous half of a koi pond, and the half you will be glad you did properly. Lasco and Valterra PVC, ball and knife gate valves, swing checks, unions, bulkhead fittings and the odd Hayward part.

Two rules worth following: use bigger pipe than you think you need, because friction loss climbs steeply as diameter drops, and put a union either side of everything you might ever service. The extra twenty dollars in fittings is what stands between a ten minute job and cutting pipe out of a wet hole.

White PVC ball valve, elbow and tee with a clear check valve and a black bulkhead fitting on a stone ledge beside a koi pond, the fittings used to plumb a koi system.

What kind of part?

Every fitting on this shelf, sorted by the job it does. Sizes are listed on each product.

Valves ValvesValterra ball, knife-gate and check valves plus 2- and 3-way diverters, 1 inch to 3 inch. Control, isolate or backflow-protect any line.Shop valves Elbows, tees & couplings Elbows, tees & couplingsLasco Sch 40 PVC in 1-1/2 and 2 inch: 45s, 90s, street elbows, tees, couplings and the sweep elbows that go easy on your pump.Shop elbows & tees Unions UnionsSelf-aligning unions, pump unions and replacement union nuts. The fitting that lets you service a pump without cutting pipe.Shop unions Adapters & bushings Adapters & bushingsMale and female thread-to-slip adapters and reducing bushings for stepping between 1-1/2 and 2 inch pipe.Shop adapters Bulkheads & bottom drains Bulkheads & bottom drainsBulkhead fittings from 3/4 inch to 4 inch, plus DreamPond KoiToilet bottom drains in 3 and 4 inch for through-liner plumbing.Shop bulkheads Suction, returns & traps Suction, returns & trapsLeaf traps and strainer baskets that keep debris out of your pump, plus suction outlets and return inlet fittings.Shop traps & returns

Worth knowing before you buy

Ground rules and answers from the ponds we run every day in San Jose.

Never run the pump dry, or the UV without flow

Mechanical seals fail in seconds without water, and a UV lamp running in a dry chamber overheats the quartz sleeve. Wire them so they start and stop together.

Put unions either side of everything

Pumps, filters, UV, valves. The extra twenty dollars in fittings is what stands between a ten minute service and cutting pipe out of a wet hole.

Common questions

What size pipe should I use?＋

Bigger than you think. Friction loss climbs steeply as pipe gets narrower, and every foot of flow you lose to undersized plumbing is flow you paid for at the pump. As a working guide: 1-1/2 inch for pressurized returns on smaller systems, 2 inch for most koi pond returns, and 3 to 4 inch for gravity-fed bottom drain lines, which move water on almost no pressure and need the diameter.

Use sweeping 45 degree bends instead of sharp 90s wherever you can, and put a union either side of every serviceable component.

Submersible or external pump?＋

Submersibles are cheaper up front, simple to install, and perfectly good on ponds under about 1,500 gallons or on a separate waterfall circuit. The downsides are that electricity sits in the water, and servicing means reaching in.

External pumps cost more but are usually cheaper to run over a season, last longer, and can be serviced without getting wet. On a koi pond of any real size, an external pump is the standard choice. One catch: most are not self-priming and must sit below the water line so the intake stays flooded. If yours has to sit higher, you need a self-priming model.

I am not sure what I need. Can you just tell me?＋

Gladly, and this is genuinely the fastest route. Send us your pond volume, your depth, roughly how many koi you keep and how big they are, your plumbing size, and the height from the pond surface up to your filter return. That is everything we need to size a system properly.

We have been building and maintaining koi ponds from San Jose since 1998, and we run this gear on our own systems. We would rather talk you into the right pump than sell you the biggest one.

Have us size your systemFull pond guide & calculator