How to set up a low-tech planted aquarium without CO2 – simple and beginner-friendly

Not every aquascaping enthusiast has the budget or setup for a full CO2 system. The good news? You don’t need one to create a lush, thriving planted aquarium! With the right approach, you can enjoy a beautiful, healthy aquascape that requires no added CO2. Let Terrarium Vibe show you how and why a non-CO2 planted tank is absolutely possible.

Why a planted tank can thrive without CO2

CO2 boosts photosynthesis, helping aquatic plants grow faster and display vibrant colors. However, in low-light conditions, plants grow more slowly and steadily—making CO2 supplementation optional.

Plus, CO2 naturally exists in the water through fish respiration and organic decomposition. By choosing the right plants and maintaining a balanced combo of light and nutrients, you can absolutely keep a stunning, low-maintenance planted aquarium without injecting CO2.

Best aquarium plants for non-CO2 tanks

Even without a CO2 system, you can grow a vibrant underwater garden using hardy, low-demand plants. These species not only thrive in low-tech setups but also bring a natural aesthetic to your aquascape.

Foreground plants

The foreground sets the first impression—opt for low-growing plants that form neat carpets or compact highlights:

• Dwarf hairgrass (Eleocharis parvula): Creates a soft, fine-textured carpet; slow-growing and CO2-free friendly.
• Pygmy chain sword (Helanthium tenellum): Short, bushy leaves that stay vibrant in moderate lighting.
• Mini moss (e.g., Christmas moss): Easy to tie to driftwood or rocks; grows thick and lush.
• Anubias petite: A compact version of Anubias with dark, dense leaves—perfect for eye-catching accents

Midground plants

Midground plants bridge the visual gap between foreground and background. Look for medium-height plants that offer natural flow and movement:

• Java fern: Soft, arching leaves that look fantastic when attached to wood or rock.
• Cryptocoryne (crypts): Slow-growing with varied leaf colors and shapes—ideal for filling space without overpowering the view.
• Ludwigia repens (some varieties): Offers subtle red or orange tones, even without CO2.
• Hygrophila polysperma (green temple): Fast-growing with delicate leaves; can be trimmed into compact bushes.

Background plants

Tall, bushy plants create depth and help conceal equipment like filters or heaters. They complete the tank’s overall composition:

• Hornwort (Ceratophyllum demersum): Rapid growth, dense green foliage, and great at absorbing excess nutrients.
• Vallisneria (jungle val): Long, ribbon-like leaves that sway with the current—great for taller tanks.
• Japanese floating fern (Salvinia natans): Though a floater, it shades the tank naturally, helping stabilize non-CO2 setups.
• Pothos (Epipremnum aureum – semi-aquatic): Grows with roots in the water; helps purify and adds greenery above the rim.

  

  Background plants

Step-by-step guide to setting up a low-tech planted aquarium (no CO2)

Step 1: Choose the right tank and lighting
A small tank (30–60 cm) is perfect for beginners.
Use a medium-bright LED aquarium light (6–8 hours/day). Avoid overly intense lighting to reduce algae.

Step 2: Prepare the substrate
Use nutrient-rich aquasoil or pre-mixed planted tank substrate.
Skip liquid fertilizers at the start to prevent algae blooms.

Step 3: Select plants and layout
Prioritize CO2-low plants like Anubias, Java ferns, crypts, and moss.
Don’t overcrowd initially—allow space for plants to adjust and root properly.

Step 4: Add fish and establish the ecosystem
After 7–10 days of cycling, introduce fish.
Choose peaceful, algae-helpful species like neon tetras, otocinclus, or shrimp.

Step 5: Routine maintenance
Change 20–30% of the water weekly. Trim dead leaves, clean glass, and monitor beneficial bacteria levels

Common mistakes in non-CO2 planted tanks

Low-tech aquariums are easier to maintain, but they’re not mistake-proof. Watch out for these common errors:

• Choosing high-demand plants: Species like glossostigma or Rotala wallichii often fail without CO2.
• Using overly strong lighting: This can trigger algae outbreaks and disrupt balance.
• Overstocking with fish/shrimp too early: Leads to cloudy water and high waste levels.
• Incorrect fertilization timing: Adding liquid nutrients too soon or in large doses fuels algae growth.

Yes—you can have a thriving, low-tech planted aquarium without CO2! By selecting the right plants, designing a smart layout, and keeping up with basic care, your tank will flourish naturally. Whether you’re new to aquascaping or looking for a simpler approach, this method offers beauty without the complexity. Terrarium Vibe wishes you success in building your perfect green corner—naturally lush, easy to maintain, and full of life.