The Ultimate Guide to Adding a Water Feature in Your DIY Hot Tub

The soothing sound of flowing water is naturally relaxing to the human ear. That’s why adding a water feature like afountain, waterfall, or small stream to your hot tub setup can seriously level up your soaking experience. It not only adds a touch of luxury but also creates a calming ambiance for you, your family, and your guests. In this post, we’ll walk you through some essential tips on how to design and install a water feature in your DIY hot tub—so let’s dive in!

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Types of Water Features

There are many different types of water features that can be added to your hot tub setup. Ideally, you’ll want to plan these into your design right from the start, as trying to retrofit them later on can be challenging, time-consuming, and more expensive.

When choosing a water feature, think beyond just the visual appeal. You’ll want one that blends in seamlessly with the rest of your backyard aesthetic, but you should also consider things like installation requirements, water flow rates, and maintenance.

Here are the main types of water features commonly used in hot tubs:

• Waterfalls
• Fountains
• Streams

They all create a soothing, tranquil sound and can even provide a gentle cooling mist on warmer days. Water features are also a great way to inject personality and style into your hot tub design.

Fountains, in particular, can be crafted from a variety of materials—acrylic, stainless steel, natural stone, or even custom-built sculptural designs. Each material brings its own vibe, from sleek and modern to earthy and rustic.

Types of Materials Used

When adding a water feature to your hot tub, it’s important to pay close attention to the materials used—especially in relation to the chemicals that will be present in your water.

Hot tub water typically contains chlorine, bromine, or other sanitizing agents, and not all materials are built to withstand those over time. For example, a fountain or water feature made for a garden pond might look the part, but it isn’t necessarily rated for use in hot tubs or swimming pools.

Why does this matter? Because if the material isn’t compatible, it can start to corrode, break down, or discolor over time, potentially ruining your feature—and worse, contaminating your water.

So, always double-check the manufacturer’s specifications and make sure the product is rated safe for use with hot tub chemicals. It’s a small detail that can save you a lot of hassle and expense down the line.

Water Feature in Your Hot Tub

In this post—just like the rest of our blog—we’re all about helping the DIY hot tub builder. So if you’re crafting your own custom setup, adding a water feature can be a fun and rewarding upgrade. That said, if you’re working with a pre-made plastic shell hot tub, I’d strongly advise against trying to modify it for a water feature. The structure just isn’t designed for that kind of customization.

Size and Space

Before you get too excited, take a step back and consider your space. Water features—especially waterfalls and fountains—often look smaller in pictures than they are in real life. Measure twice, plan once. You want to be sure your hot tub area can handle the addition without feeling cramped or awkward.

Positioning

Where are you thinking of placing your water feature? Will it sit at the end of a rectangular tub, be integrated into a wall, or even rise up from the center of a circular hot tub? Placement affects not just aesthetics, but also water flow and splash pattern—so be strategic.

Flow Rates

Waterfall flow rates are typically measured in gallons per minute (GPM) or gallons per hour (GPH), and this is where things can get tricky. You need to make sure your chosen water feature doesn’t overpower your system.

If it’s a low-flow feature, you’re probably fine. But if it’s pumping out more than 1000 GPH, then it’s time to do some pump math.

Ask yourself:

• What’s the maximum flow rate of your pump?
• How many jets will be running alongside the waterfall?
• When you add up all the demands (jets + water feature), do they stay within your pump’s max flow capacity?

You want each component to get the water pressure it needs—without sacrificing performance.

Flow Control

There are two main aspects to controlling a water feature:

1. Controlling the flow
2. Controlling the feature itself

Let’s tackle flow first.

The most common and effective method? A ball valve—also called a waterfall regulator. This simple, manual device lets you tweak how much water flows out of your feature until it looks just right.

Too much pressure? Use an inlet reducer. A smaller pipe means less water flow. It’s a basic trick, but incredibly effective.

Pro tip: If your waterfall ends up shooting a wild horizontal blast across your yard… it’s time to tone things down.

Independent Pumping (Highly Recommended)

Whenever possible, I recommend giving your water feature its own dedicated pump. Why?

• It lets you turn the feature on and off independently.
• You won’t have to compromise the flow to your jets, which are essential for a great soak.
• It simplifies maintenance and control.

Bottom line: Separate systems = smoother operation and more flexibility.

Where do I connect a Water Feature in the Hot Tub plumbing?

In short, you dont!

The best way to plumb in a hot tub is to put the water feature onto its own pump and have its own inward suction. In that way, you are not affecting the flow rates on the jets or disturbing the circulation and filtration process.

The plumbing for a water feature is simple and should look something like this.

How do I turn the Water Feature on or Off?

When you are designing the water feature, you need to decide how you are going to control it. For example, if your hot tub has a waterfall, the chances are you only want it to run when you are in the tub. Otherwise, it would empty the tub onto the cover!

By putting this on its own pump, you can control when the pump is on or off. However, what if this is part of a larger feature and you want to control individual elements? 

You could simply opt for a manual adjusted stop valve or ball valve. Turn the handle to lock the water off or switch it on. Pretty simple stuff.

However, some customers want to be able to “switch” their water features (or parts of) on or off. In order to do this, you need to use a Solenoid Valve.

What is a Solenoid Valve?

– A solenoid valve is a type of electronic valve that opens and closes with the use of an electric current. It’s practically impossible to turn it on or off by hand, so this can be useful if you want your water feature to operate automatically or at certain times simply connect the valve to a timer.

There are two main types:

• Normally Closed (NC) – The valve stays closed when there’s no power. It only opens when powered.
  Best choice if you want the feature off by default (like a waterfall that only runs while you’re using the tub).
• Normally Open (NO) – The valve stays open when there’s no power. It only closes when powered.
  Ideal if your feature runs most of the day and you only want to stop it occasionally.

What to Look For When Buying a Solenoid Valve

• Voltage Compatibility – Solenoid valves come in different voltages: 12V, 24V, 110V, 240V, etc. Make sure you get one that matches your power setup.
• Pipe Size Matters – The valve size should match the diameter of the pipe leading to your water feature. Most DIY builds will use 1.5″ pipe, but you can always use adapters to convert sizes if needed.
• Timer Integration – Want your feature to run at specific times? Hook up the solenoid valve to a smart timeror control system. You’ll get that clean, modern, hands-off experience—no valve turning required.

How to Install a Solenoid Valve in Your Plumbing Setup

The solenoid valve needs to be installed after any check valves and pressure relief valves, since it only allows water to flow in one direction when powered.

If you don’t already have a spot for the solenoid valve, you can also install a manual ball valve downstream. This will still allow you to control flow manually in case you need a backup or prefer manual operation.

⚠️ Important Note: A solenoid valve is either fully open or fully closed—there’s no halfway or partial flow. Plan accordingly.

There will be a directional flow indicator (usually an arrow) on the valve itself. Make sure you align it correctly to match the water flow direction in your system. Getting this wrong will cause issues with water pressure and flow.

Let’s say we’re installing a 240V 1″ Solenoid Valve, labelled “A” in the diagram.

Here’s how the setup would typically go:

1. Start with a 1″ socket to male thread adapter – labeled “B”. This allows you to reduce your 1.5″ hot tub pipework down to 1″.
2. Connect a short piece of 1″ white pipe – labeled “C”.
3. Use a 1″ to 1.5″ reducing bush – labeled “D”, which fits inside a 1.5″ socket – labeled “E”.
4. Take note of the direction of the flow arrow on the solenoid valve (A). In this example, the flow goes from left to right.

Once connected:

• The left-hand side (inlet) would be plumbed to the main water supply (usually coming off the jet lines).
• The right-hand side (outlet) connects directly to your water feature.

 

Wiring It Up

This solenoid valve is a Normally Closed (NC) model, so it stays closed until power is applied.

• Wire the valve into your main electric supply.
• Add a simple inline switch to the positive wire.
  Flip the switch ON → the valve opens → water flows to the feature.
  Switch OFF or power outage → the valve automatically closes → no water flow.

This is a simple but reliable solution to control your hot tub water feature. You don’t need complex automation unless you want to get fancy.

Final Thoughts

Installing a solenoid valve can make your DIY hot tub setup feel more professional and high-end. With a switch or timer, you’re in full control—and in case the power ever goes out, the valve will simply close without it.

Hope you found this guide helpful.

Happy Hot Tubbin’!

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Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi