Planted Hexagon Aquarium – The Ultimate Guide To Vertical Aquascaping

There is something undeniably captivating about a planted hexagon aquarium. While standard rectangular tanks offer a wide panoramic view, the hexagon tank provides a unique, 360-degree perspective that turns a slice of nature into a living piece of art. If you have ever felt limited by the horizontal “box” of traditional tanks, you are in the right place.

I know that setting up a planted hexagon aquarium can feel a bit intimidating at first. You might be worried about how to reach the bottom for maintenance or how to get enough light to your ground-cover plants. Don’t worry—this setup is actually perfect for hobbyists who want to experiment with verticality and depth!

In this guide, I will share my years of experience to help you navigate the specific challenges of hexagon tanks. We will cover everything from choosing the right species like Vallisneria spiralis to ensuring your light penetrates the deep water column. By the end, you’ll have the confidence to create a thriving, lush masterpiece in your own home.

Understanding the Unique Physics of a Planted Hexagon Aquarium

Before we dive into the plants and hardscape, we need to talk about the “why” behind the design. Hexagon tanks are taller than they are wide, which changes the way light and oxygen move through the water. This vertical orientation is beautiful, but it requires a slightly different approach than a standard “long” tank.

The Challenge of PAR Attenuation

One of the most critical factors in a tall tank is PAR attenuation. PAR (Photosynthetically Active Radiation) refers to the amount of light available for your plants to photosynthesize. In a deep hexagon tank, the light has to travel through more water to reach the bottom.

As light travels deeper, it loses intensity. This means a light that works perfectly on a 10-gallon rectangular tank might be too weak for a 20-gallon hexagon. To solve this, you need a light source with a strong “punch” or a narrow beam angle to ensure your foreground plants don’t starve for energy.

Surface Area and Gas Exchange

Hexagon tanks have a smaller surface area relative to their volume compared to rectangular tanks. Because gas exchange happens at the surface, you have to be more intentional about oxygenation. This is where vertical water column circulation becomes your best friend.

You want to ensure that water from the bottom is constantly being pushed toward the surface. A good filter with an adjustable spray bar or a small internal powerhead can prevent “dead zones” where waste accumulates and oxygen levels drop. This is vital for both your fish and the aerobic bacteria in your substrate.

Mastering the Layout of Your Planted Hexagon Aquarium

When designing a planted hexagon aquarium, you have to think in three dimensions. In a rectangular tank, we usually think about “left to right,” but here, we think “center to edges.” A central island composition is often the most striking choice for this footprint.

Building the Central Pillar

Because you can view the tank from multiple sides, placing your tallest hardscape elements in the center is a classic move. Large pieces of driftwood or tall rock pillars create a focal point that draws the eye upward. This mimics the look of a sunken tree stump or a rocky spire in a river.

When selecting your base, consider the substrate cation exchange capacity (CEC). Using a high-CEC soil ensures that nutrients are held within the root zone rather than leaching into the water column. You can learn more about choosing a nutrient-rich foundation to support this central growth.

Creating Depth with Tiers

To make the tank look natural, use different “tiers” of height. Place your tallest plants right against your central hardscape. As you move toward the glass panels, transition to mid-sized plants and finally low-growing mosses or carpets. This creates a sloped effect that makes the small footprint feel much larger than it actually is.

Choosing the Best Plants for Vertical Growth

Not every plant is suited for a tall environment. You want species that naturally reach for the surface or those that can thrive in the lower-light conditions found at the bottom of a deep tank. Here are my top recommendations for a planted hexagon aquarium.

Tall Background and Centerpiece Plants

Vallisneria spiralis is an absolute must-have for hexagon tanks. Its long, ribbon-like leaves will grow straight up to the surface and then trail across the top, providing a beautiful “jungle” look. It also helps provide cover for taller fish like Pterophyllum scalare (Angelfish).

Another excellent choice is Echinodorus amazonicus, commonly known as the Amazon Sword. This plant grows wide and tall, making it a perfect centerpiece. For a more unique, grassy look that stays upright, try Cyperus helferi. It has a distinct architectural quality that complements the geometric shape of the hexagon.

Mid-Ground and Epiphytes

Since the center of your tank will likely feature wood or rock, you should take advantage of epiphytes. These are plants that grow attached to hardscape rather than buried in the soil. Anubias barteri and Microsorum pteropus (Java Fern) are incredibly hardy and can handle the lower light levels of the mid-tank region.

Tucking Microsorum pteropus into the crevices of your central pillar adds texture and hides any unsightly glue or thread used to secure the hardscape. These plants are slow growers, meaning they won’t quickly outgrow their space and require constant trimming.

Vertical Plant Placement Guide

Zone	Recommended Species	Light Requirement	Benefit
Background/Center	Vallisneria spiralis	Moderate	Creates a tall, swaying curtain effect.
Centerpiece	Echinodorus amazonicus	Moderate to High	Provides a massive, leafy focal point.
Attached to Wood	Anubias barteri	Low to Moderate	Easy care; thrives in shaded areas.
Mid-Ground Spacing	Cyperus helferi	Moderate	Unique vertical texture; doesn’t spread fast.
Foreground/Bottom	Cryptocoryne wendtii	Low	Handles the lower light at the tank floor.

Essential Equipment for a Thriving Hexagon Tank

To keep your planted hexagon aquarium healthy, your equipment needs to be tailored to the depth of the water. Standard “kit” filters and lights often fall short in these taller dimensions.

High-Output Lighting

As we discussed with PAR attenuation, you need a light that can penetrate 18 to 24 inches of water. LED fixtures with 60-degree or 90-degree lenses are ideal because they focus the light downward rather than scattering it. Look for a light that allows you to adjust the spectrum to ensure your plants get enough blue and red peaks for growth. You can find more details in our optimal light intensity guide.

CO2 and Nutrient Delivery

If you decide to run a high-tech tank with demanding plants, CO2 is a game-changer. However, getting CO2 to dissolve efficiently in a tall tank can be tricky. I highly recommend using a CO2 inline atomizer connected to your canister filter return line.

This device creates a fine mist of CO2 bubbles that are thoroughly mixed with the water before they even enter the tank. This ensures that the CO2 is evenly distributed by the vertical water column circulation, reaching the plants at the very bottom as well as those near the top.

Filtration Strategies

A canister filter is usually the best choice for a hexagon tank. It allows you to place the intake near the bottom and the output near the top, creating a loop that prevents stagnant water. If you use a hang-on-back filter, make sure the intake tube is extended as deep as possible to pull waste from the substrate level.

Best Fish and Shrimp for Hexagon Tanks

Stocking a planted hexagon aquarium requires a bit of thought. Because there is less horizontal swimming space, you should avoid “high-speed” swimmers like giant danios. Instead, look for fish that appreciate vertical height or those that hover in place.

The Majesty of Pterophyllum scalare

Angelfish (Pterophyllum scalare) are perhaps the most iconic choice for a tall tank. Their thin, tall bodies are perfectly adapted for navigating through vertical plants like Vallisneria. A pair of Angelfish can easily become the stars of a 30-gallon or larger hexagon tank.

Nano Fish and Shrimp

If you have a smaller hexagon tank, consider a large school of Chili Rasboras or Neon Tetras. While they are small, a group of 15-20 moving together through the tiered plants looks stunning. For the bottom, Amano shrimp or Cherry shrimp are excellent for algae control. Just be sure to provide plenty of moss for them to hide in!

Maintenance Tips for Tall Aquariums

Let’s be honest: cleaning a tall tank can be a bit of a workout for your arms! However, with the right tools, your weekly care routine doesn’t have to be a chore.

• Long-Handled Tools: Invest in 24-inch tweezers and scissors. These allow you to prune plants at the bottom without submerging your entire shoulder in the water.
• Magnetic Scrapers: A strong magnetic glass cleaner is essential for keeping those six panels of glass clear of algae without reaching in every day.
• Gravel Vacuums: Use a siphon with a long rigid tube to reach the substrate easily.

Regularly check your plants for signs of nutrient deficiency. In tall tanks, the plants at the bottom are the first to show signs of struggle if the light or CO2 isn’t reaching them. If you notice yellowing leaves on your Cryptocorynes, it might be time to increase your fertilization or clean your light’s splash guard.

Frequently Asked Questions (FAQ)

Is a hexagon tank good for a planted aquarium?

Yes! While they offer some challenges regarding light penetration and surface area, they are excellent for creating unique vertical aquascapes. They are especially good for plants that grow tall and fish that prefer vertical swimming space.

How do I get enough light to the bottom of a tall hexagon tank?

Focus on LED lights with high PAR ratings and narrow lenses (60-90 degrees). This minimizes light scatter and ensures the energy reaches the foreground plants. You may also want to choose low-light plants for the very bottom of the tank.

What are the best plants for a hexagon aquarium?

Tall species like Vallisneria spiralis and Echinodorus amazonicus are perfect for the background. Epiphytes like Anubias barteri and Microsorum pteropus work well on central hardscape, while Cyperus helferi adds great vertical texture.

Can I keep Angelfish in a hexagon tank?

Yes, provided the tank is large enough (usually 30 gallons or more). Pterophyllum scalare naturally inhabit waters with vertical branches and tall plants, making the hexagon shape a great fit for their body type.

Do I need a CO2 system for my hexagon tank?

It depends on your plant choice. If you are growing easy plants like Java Fern and Anubias, you can skip it. However, for a lush, high-growth look, a CO2 inline atomizer will help overcome the challenges of gas exchange in a tall water column.

Conclusion

Creating a planted hexagon aquarium is a rewarding journey that challenges you to think differently about space and design. By understanding the physics of light depth and ensuring proper vertical water column circulation, you can overcome the common pitfalls of this unique tank shape.

Remember to choose your plants wisely—mixing tall species like Vallisneria spiralis with hardy epiphytes like Microsorum pteropus will create a balanced and resilient ecosystem. Whether you are housing a graceful pair of Pterophyllum scalare or a bustling colony of shrimp, your hexagon tank will undoubtedly be the focal point of any room.

Don’t be afraid to experiment with your central hardscape and play with different heights. With a little patience and the right equipment, your vertical underwater garden will thrive for years to come. Happy aquascaping!