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SLW-10 Fish Guard & Anemone Guard Design and Creation | Protecting Reef Tank Livestock

SLW-10, MLW-10 & DLW-10 Fish Guard and Anemone Guard Design & Creation

Protecting Reef Tank Livestock from Wave Pump Accidents

One of the most common—and heartbreaking—accidents in the reef aquarium hobby happens when a wandering anemone, curious fish, snail, or shrimp encounters an unprotected wave pump.

For many reef keepers, it happens without warning. A healthy anemone decides to move overnight. A small fish gets too close to a powerhead. A snail finds its way onto an intake screen. By the next morning, the results can range from damaged livestock to a complete tank crash.

That exact concern inspired the creation of this project.

In this video and article, I take you through the complete design, engineering, 3D printing, testing, and production process behind a custom Fish Guard and Anemone Guard designed specifically for the Jebao SLW-10, MLW-10, and DLW-10 wave pumps.

The goal was simple:

Create a guard that protects reef tank livestock while maintaining the exceptional flow performance that makes these pumps so popular.

Understanding the SLW-10, MLW-10 and DLW-10

Before diving into the design process, it's important to understand the relationship between these pumps.

Many reef hobbyists believe the SLW-10, MLW-10, and DLW-10 are completely different products. In reality, they share the same pump body and wet-side assembly.

The primary differences are found in the controller systems.

SLW-10

The SLW-10 utilizes a traditional wired controller and has become one of the most widely used budget-friendly reef pumps on the market.

MLW-10

The MLW-10 adds WiFi connectivity and app-based control while retaining the same pump housing.

DLW-10

The DLW-10 builds on the platform with updated wireless functionality and enhanced programming options.

Because the physical pump remains the same, a properly designed fish guard can fit all three models.

This means one solution protects users regardless of which controller version they own.

Why Reef Keepers Need Fish Guards

Wave pumps are essential for reef tank success.

Corals depend on water movement for:

  • Nutrient delivery

  • Gas exchange

  • Waste removal

  • Growth and health

  • Polyp extension

Without proper flow, reef tanks struggle.

However, the same pumps that help corals thrive can create risks for livestock.

Common pump-related accidents include:

Wandering Anemones

Anemones occasionally relocate when searching for:

  • Better lighting

  • Different flow

  • Improved footing

  • More stable conditions

If an anemone reaches a powerhead intake, the results can be catastrophic.

Small Fish

Young clownfish, gobies, blennies, dartfish, and other smaller species may occasionally become trapped against strong intakes.

Snails

Turbo snails, trochus snails, and other cleanup crew members often explore powerheads and can interfere with operation.

Shrimp and Invertebrates

Cleaner shrimp and other mobile invertebrates sometimes venture into areas that create unnecessary risk.

A fish guard helps provide an additional layer of protection without sacrificing water movement.

Defining the Design Goals

Like any engineering project, success starts with clearly defining the objectives.

The guard needed to:

Protect Livestock

The primary objective was protecting fish, anemones, snails, shrimp, and other reef inhabitants.

Preserve Water Flow

A guard that dramatically reduces flow creates a new problem while solving another.

Maintaining strong circulation was critical.

Look Like It Belongs

Many aftermarket accessories look bulky or awkward.

The goal was to create something that looked like it could have shipped from the factory.

Install Easily

No modifications.

No tools.

No permanent changes.

The guard needed to snap into place and remain secure.

Be Durable

Saltwater is a harsh environment.

The final design needed to withstand years of use inside a reef aquarium.

Building a Digital SLW-10 Reference Model

Every successful product begins with accurate measurements.

The first step involved carefully measuring every critical feature of the pump.

This included:

  • Outer dimensions

  • Intake geometry

  • Mounting surfaces

  • Curves and contours

  • Clearance areas

  • Flow openings

Once collected, these measurements were recreated inside CAD software to create an accurate digital model.

This digital reference became the foundation for all future design work.

The Engineering Challenges

Designing a fish guard sounds simple.

In reality, it creates several competing priorities.

More Protection = Less Flow

Smaller openings provide more protection but restrict circulation.

More Flow = Less Protection

Larger openings maximize water movement but increase risk.

Structural Strength

Thin structures improve flow but may reduce durability.

Ease of Cleaning

Complex geometries can become difficult to maintain.

Finding the balance between these competing factors required multiple design iterations.

Designing the Fish Guard

The first phase focused on protecting fish and invertebrates.

Several concepts were explored.

Each design attempted to maximize open surface area while reducing the likelihood of livestock reaching the intake.

Numerous adjustments were made to:

  • Opening size

  • Surface area

  • Structural ribs

  • Attachment methods

  • Flow pathways

Each revision improved performance and usability.

Designing the Anemone Guard

Anemones required a separate set of considerations.

Unlike fish, anemones can deform and squeeze through surprisingly small spaces.

This meant the guard needed to provide broader protection while still maintaining circulation.

Several versions were created before arriving at the final design.

The resulting guard provides substantially more protection while maintaining the broad flow characteristics reef hobbyists expect from the SLW, MLW, and DLW platforms.

From CAD to Reality: 3D Printing

With the design complete, it was time to begin prototyping.

This is where 3D printing becomes invaluable.

Rather than waiting weeks for production tooling, prototypes could be produced within hours.

Each prototype was evaluated for:

  • Fitment

  • Flow performance

  • Durability

  • Installation

  • Visual appearance

Every version revealed opportunities for improvement.

The design evolved through multiple generations before reaching the final production model.

Testing Inside Real Reef Aquariums

Computer models only tell part of the story.

Real-world testing is where products prove themselves.

The guards were tested under realistic reef tank conditions to evaluate:

Flow Characteristics

Did the pump still create strong circulation?

Livestock Safety

Did the design provide meaningful protection?

Long-Term Durability

Would the guard withstand continuous operation?

Ease of Maintenance

Could hobbyists easily remove and clean the guard?

The final design successfully balanced all of these requirements.

Final Production Materials

After extensive testing, the final design transitioned to professional manufacturing.

The production version utilizes durable materials suitable for long-term reef aquarium use.

Benefits include:

  • Excellent durability

  • Precise fitment

  • Consistent quality

  • Reef-safe performance

  • Long service life

Benefits of the Finished Guard

The final Fish Guard and Anemone Guard provide:

Fish Protection

Helps reduce the risk of fish contacting the intake.

Anemone Protection

Provides an additional layer of protection against wandering anemones.

Snail Protection

Helps prevent snails from interfering with pump operation.

Maintained Flow

Designed to preserve the broad flow pattern of the original pump.

Easy Installation

Installs in seconds without modifying the pump.

Clean Appearance

Complements the original pump design.

Who Should Consider a Fish Guard?

This accessory is especially beneficial for reef keepers who keep:

  • Bubble Tip Anemones

  • Rock Flower Anemones

  • Small Clownfish

  • Gobies

  • Blennies

  • Firefish

  • Shrimp

  • Snails

  • Mixed reef systems

If you've ever worried about a wandering anemone reaching your powerhead, a guard can provide valuable peace of mind.

Watch the Complete Design and Creation Process

This project involved countless hours of:

  • Measuring

  • Designing

  • CAD modeling

  • 3D printing

  • Testing

  • Refinement

  • Production development

Watch the full video to see the entire process from initial concept to finished product.

Whether you're interested in reef aquariums, product development, engineering, or 3D printing, there's something here for everyone.

Frequently Asked Questions

Does this fit the SLW-10?

Yes.

Does this fit the MLW-10?

Yes.

Does this fit the DLW-10?

Yes.

Why does one guard fit all three pumps?

Because the SLW-10, MLW-10, and DLW-10 share the same wet-side pump housing. The only differences are the controllers.

Does the guard reduce flow?

Any guard creates some restriction, but this design was optimized to preserve as much flow as possible.

Will it completely prevent anemone accidents?

No guard can guarantee complete protection, but it significantly reduces the likelihood of an anemone reaching the impeller.

Is it reef safe?

Yes, the production version was designed specifically for use in saltwater aquariums.

More Reef Tank Designs Coming Soon

The SLW-10, MLW-10, and DLW-10 Fish Guard project is part of an ongoing effort to create innovative reef aquarium accessories that solve real-world problems for reef keepers.

Future projects include:

  • Wave pump guards

  • Fish guards

  • Anemone guards

  • Roller mat accessories

  • Powerhead accessories

  • Custom reef equipment

  • New 3D printed aquarium products

Subscribe to the iSeaLive YouTube channel and follow along as future projects move from concept sketches to finished products.

Every great reef tank deserves equipment designed with both performance and livestock safety in mind.

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