Nano Planted Tank Setup Guide (10–40L)

Published 3 June 2026

Nano planted tanks — generally defined as setups under 40 litres — are some of the most visually striking displays in the freshwater hobby. A 30cm cube filled with dense moss, bright shrimp, and a single piece of driftwood can be genuinely beautiful in a way that competes with much larger setups.

They’re also more challenging than larger tanks. Small water volumes mean parameters swing quickly, errors have faster consequences, and livestock choices are more constrained. Get the setup right from the start and nano tanks are manageable; cut corners and they’re frustrating.

Here’s how to do it correctly.

Is a nano tank right for you?

Choose nano if:

• You have limited space and can’t accommodate a larger setup
• You want a desktop or countertop display
• You’re primarily interested in shrimp and nano fish rather than larger species
• You’re comfortable with the need for more frequent monitoring

Consider a larger tank (40–75L) if:

• This is your first aquarium ever — larger tanks are more forgiving
• You want to keep a betta as the centrepiece (40L minimum is better for bettas)
• You want to keep a small community of fish with more stocking options

The most common mistake with nano tanks is treating them exactly like a larger tank with smaller fish. They’re not — they require a different approach to stocking, maintenance, and intervention speed.

The right nano tank size

20–30L (5–8 gallons) is the sweet spot for a beginner nano setup. Small enough to be genuinely compact; large enough to maintain reasonable stability.

10–15L tanks are possible for experienced hobbyists with shrimp-only setups, but they require daily monitoring and very precise management. Not recommended as a first aquarium.

The 30cm cube (27L) is the most popular nano planted tank format in the hobby — the cube shape gives excellent depth for aquascaping and fits comfortably on a desk.

Equipment for a nano planted tank

Filter

Sponge filter: The best choice for most nano setups, especially shrimp tanks. Air-powered, gentle flow, excellent biological filtration, safe for shrimplets.

Small internal filter: Compact units like the Azoo Mignon 60 or Eheim Pickup suit nano tanks needing slightly more flow than a sponge filter provides. Cover the intake with foam if keeping shrimp.

HOB filter (nano size): Options like the Aquaclear 20 can work for 20–30L tanks. Cover the intake for shrimp tanks. The flow is usually adjustable down to appropriate levels.

Heater

Nano heaters (25–50W, submersible, adjustable) are available for small tanks. Alternatively, a standard 50W heater works fine for tanks down to 20L. Temperature stability is critical in nano tanks — small volumes heat and cool faster, so consider whether your room temperature is stable before deciding whether a heater is necessary.

Lighting

For a low-tech nano planted tank, a moderate LED rated for the tank size at 6–8 hours per day is sufficient. Many purpose-built nano tank lids include adequate LEDs. Clip-on lights (Hygger and Nicrew make small options) work well for rimless nano tanks.

Keep it modest — low light in a small tank prevents the algae problems that commonly plague over-lit nano setups.

Substrate

Aquasoil at 5–7cm depth is the best choice for a planted nano tank. Dark aquasoil shows off coloured shrimp particularly well. The nutrient content means plants establish quickly without supplemental fertilisation in the first year.

Best plants for nano tanks

The ideal nano tank plant is compact, slow-growing (so it doesn’t outgrow the space), and thrives in low light without CO2.

Top choices:

• Anubias nana / nana ‘petite’ — small, attaches to hardscape, almost maintenance-free
• Bucephalandra — slow-growing, compact, high biofilm surface area (great for shrimp)
• Java moss — essential for shrimp tanks; provides biofilm and cover
• Miniature java fern (Microsorum pteropus ‘Mini’) — smaller version of the standard java fern
• Cryptocoryne parva / willisii — small crypt varieties that suit nano foregrounds
• Floating plants (frogbit, salvinia) — essential for nutrient control in small tanks

Avoid large or fast-growing plants in nano tanks — amazon swords, tall crypts, and large stem plants quickly overtake a small setup.

See our full best plants for shrimp tanks guide for more detail.

Stocking a nano planted tank

Nano tanks have two excellent stocking approaches:

Shrimp-only

A shrimp-only nano planted tank is the most popular and arguably the most visually effective option. Cherry shrimp (Neocaridina) in a 30cm cube with java moss and anubias provide colour, movement, and constant activity at a level that larger fish never do.

A colony of 20–30 cherry shrimp in a 30L planted tank is an established, beautiful, low-maintenance display. It’s also very forgiving — individual shrimp losses don’t devastate a colony.

See our cherry shrimp care guide for setup and breeding detail.

Nano fish community

If you want fish in a small tank, choose species specifically suited to nano setups:

• Ember tetras — 2cm, schooling, extremely peaceful, stunning in a planted tank. 8–10 in a 30L is a good community.
• Chili rasboras — similar to ember tetras, also excellent.
• Pygmy corydoras (Corydoras pygmaeus) — tiny bottom dwellers that stay under 3cm. Keep in groups of 6+.
• Celestial pearl danio — small, beautifully marked, active.
• Endler’s livebearers — tiny, colourful, peaceful.

Avoid in nano tanks: any fish that grows over 5cm, bettas in tanks under 20L, aggressive or nippy species, schooling fish that need large groups (like neon tetras, which need 8+ and prefer more space than a 20L provides).

Cycling a nano tank

Cycling a nano tank is the same process as a larger tank, but with less tolerance for error. Small volumes mean ammonia and nitrite spike faster and higher when the cycle is incomplete.

Fishless cycling is strongly recommended for nano tanks, especially if keeping shrimp. Shrimp are more sensitive than fish to ammonia and nitrite fluctuations.

See our how to cycle a fish tank guide for the complete process.

Maintenance

Nano tanks require slightly more attentive maintenance than larger setups:

Frequency:

• Water changes: 15–20% weekly (or more frequently in a new tank)
• Glass cleaning: weekly (small tanks show algae more visibly)
• Trim floating plants: as needed when surface coverage exceeds 40%
• Test water: weekly until established, monthly after

The key discipline: small water changes, small adjustments, frequent but light maintenance. The impulse to do a massive water change when something looks off is more dangerous in a nano tank than in a larger one — large chemistry swings in a small volume stress inhabitants severely.

Common nano tank mistakes

Overstocking: The “1cm of fish per litre” rule breaks down in small volumes. Stock conservatively — fewer fish with good water quality is always better than a full stock with poor water quality.

Infrequent water changes: Nano tanks produce waste in proportion to their stocking; that waste becomes concentrated faster. Weekly water changes are the non-negotiable foundation of nano tank maintenance.

Forgetting top-offs: Small tanks evaporate meaningfully between water changes. As water evaporates, the concentration of everything in it (minerals, nitrates) increases. Top off with dechlorinated tap water between water changes to maintain stable water level and chemistry.

Buying plants without checking size: Many popular aquarium plants (amazon sword, large crypts, tall val) outgrow a nano tank within months. Check mature size before purchasing.

For a complete overview of planted tank setup from the ground up, see our low-tech planted tank beginners guide.