Nero 3 Fish Guard & Anemone Guard Design and Creation | Aqua Illumination Reef Tank Protection

The Aqua Illumination Nero 3 is one of the most popular wave pumps in the reef aquarium hobby. Its compact size, powerful flow, and sleek appearance make it an excellent choice for reef keepers looking to create strong water movement without cluttering their display tank.

Unfortunately, like many high-performance wavemakers, the Nero 3 can also pose a risk to wandering anemones, small fish, snails, shrimp, and other livestock. A single encounter with an unprotected powerhead can result in injury, loss of livestock, or even a tank crash if an anemone is pulled into the pump.

That concern is what sparked this project.

In this build, I'll walk through the complete design and creation process behind the Nero 3 Fish Guard and Anemone Guard—from initial measurements and CAD design to 3D printing, testing, and final production.

If you've ever worried about protecting your reef tank livestock while maintaining strong water flow, this project was built for you.

Why Does the Nero 3 Need a Fish Guard?

The Nero 3 generates a significant amount of flow relative to its size. While this makes it fantastic for coral health and circulation, it also creates potential hazards for certain tank inhabitants.

Common risks include:

• Wandering anemones being pulled into the intake
• Small fish getting trapped against the guard
• Snails entering the intake openings
• Shrimp and invertebrates getting too close to moving components
• Coral tissue damage from direct contact

Most reef keepers don't think about these issues until they experience one firsthand.

After hearing from hobbyists and encountering similar concerns in my own reef tanks, I decided it was time to create a dedicated protection solution specifically for the Aqua Illumination Nero 3.

The Goal: Maximum Protection with Minimal Flow Loss

Designing a successful fish guard sounds simple until you begin balancing all the competing requirements.

The guard needed to:

• Protect fish and anemones
• Prevent snails from entering the intake
• Maintain strong water flow
• Preserve the Nero 3's compact appearance
• Install easily
• Be durable in a saltwater environment
• Minimize maintenance requirements

Making the openings too small would restrict flow and require constant cleaning.

Making the openings too large would compromise protection.

Finding the right balance became the central challenge of the project.

Creating a Precise Nero 3 Reference Model

Every successful product starts with accurate measurements.

The first step was creating a detailed reference model of the Nero 3 itself. This process involved carefully measuring critical dimensions, contours, intake geometry, mounting surfaces, and clearances.

Once the measurements were collected, I recreated the pump in CAD software to establish a precise digital foundation for the design.

Having an accurate 3D model allows new designs to be tested virtually before ever printing a prototype, dramatically speeding up development and improving fitment.

Designing the Nero 3 Fish Guard

With the reference model complete, the design process could begin.

Several key priorities guided the design:

Livestock Protection

The primary objective was preventing fish, anemones, and invertebrates from reaching dangerous areas of the pump.

Water Flow Performance

A fish guard that significantly reduces flow defeats the purpose of using a high-performance wave pump.

The guard needed to maximize open surface area while still providing meaningful protection.

Easy Installation

No hobbyist wants a complicated installation process.

The design needed to snap securely onto the Nero 3 while remaining easy to remove for cleaning and maintenance.

Visual Appearance

One of the reasons hobbyists choose the Nero 3 is its clean, modern appearance.

The guard needed to complement the pump rather than make it look bulky or oversized.

Designing the Nero 3 Anemone Guard

Anemones create a unique challenge in reef aquariums.

Even healthy, established anemones can occasionally decide to move. Unfortunately, powerheads often become an unintended destination.

The results can be devastating:

• Injured or destroyed anemones
• Cloudy water
• Nutrient spikes
• Damage to neighboring corals
• Potential tank crashes

The Nero 3 Anemone Guard was specifically designed to provide an additional layer of protection against these scenarios while preserving the pump's performance.

Multiple intake geometries were explored during development to determine the best combination of protection and flow efficiency.

From CAD Design to 3D Printing

Once the initial design was complete, it was time to bring the concept into the real world.

Using 3D printing allowed rapid iteration and testing.

Several prototype versions were produced, each focused on improving:

• Fitment
• Strength
• Water flow
• Printability
• Ease of cleaning
• Visual appearance

Rarely does a design work perfectly on the first attempt.

Each prototype revealed opportunities for refinement that ultimately led to a stronger final product.

Prototype Testing and Refinement

Testing is one of the most important parts of product development.

Every version of the guard was evaluated for:

Fitment

Did it install correctly?

Did it remain secure during operation?

Flow Performance

Was water movement maintained?

Were there any dead spots or excessive restrictions?

Durability

Could it withstand long-term use in a reef environment?

Maintenance

Would algae buildup create unnecessary cleaning challenges?

Each round of testing provided valuable feedback and helped shape the next revision.

Final Production in Nylon 12

Once the design was finalized, production shifted to professional-grade Nylon 12.

Nylon 12 offers several advantages for reef aquarium applications:

• Excellent durability
• Strong impact resistance
• High dimensional accuracy
• Long-term stability
• Complex geometry support

The final product combines the precision of CAD design with the durability required for long-term reef tank use.

Benefits of the Nero 3 Fish Guard and Anemone Guard

The finished design provides several key benefits for reef keepers:

Fish Protection

Helps reduce the risk of fish becoming trapped against the intake.

Anemone Protection

Provides an additional layer of defense against wandering anemones.

Invertebrate Protection

Helps keep snails, shrimp, and other livestock away from the intake.

Maintained Flow

Designed to preserve the strong circulation that makes the Nero 3 so effective.

Easy Maintenance

Simple installation and removal make routine cleaning straightforward.

Clean Appearance

Maintains the sleek look of the original Aqua Illumination Nero 3.

Watch the Complete Design and Creation Process

This project involved countless hours of measuring, designing, printing, testing, refining, and redesigning.

If you're interested in reef aquarium equipment, 3D printing, product development, engineering, or DIY reef tank projects, be sure to watch the full video where I walk through the complete creation process from concept to final product.

The video covers:

• Initial design concepts
• CAD modeling
• 3D printing
• Prototype testing
• Design revisions
• Final production

Frequently Asked Questions

Does the Nero 3 Fish Guard reduce flow?

Any intake guard will create some level of restriction, but the design was optimized to minimize flow loss while maximizing livestock protection.

Will a fish guard protect my anemone?

No guard can guarantee complete protection, but a properly designed anemone guard can significantly reduce the risk of an anemone reaching the pump intake.

Is the Nero 3 Fish Guard reef safe?

The final production version is manufactured using materials selected specifically for reef aquarium use.

Why not just use foam covers?

Foam covers often require frequent cleaning, can reduce flow significantly, and may become visually intrusive inside a display tank. This design was created to provide protection while maintaining aesthetics and performance.

Can small fish still use the Nero 3 safely?

A fish guard provides additional protection for smaller fish and livestock, making the Nero 3 safer for a wider range of reef aquarium inhabitants.

More Reef Tank Designs Coming Soon

This project is part of an ongoing effort to create practical reef aquarium accessories that solve real-world problems.

Future projects will continue to focus on:

• Fish guards
• Anemone guards
• Wave pump accessories
• Reef tank equipment
• Custom aquarium solutions
• 3D printed reef products

Be sure to subscribe to the iSeaLive YouTube channel and follow along as new ideas move from sketchbooks to finished products.

Thanks for joining me on another design and creation journey.

See you in the next build.