Nano aquariums, tanks under 30 litres, are one of the most appealing setups in the hobby. They fit on a desk, look stunning as a planted display, and cost relatively little to set up. But they're also more technically demanding than larger tanks. This guide tells you how to succeed with a nano setup.
Why Nano Tanks Are Harder (and How to Handle It)
In a small volume of water, everything happens faster: temperature swings, ammonia spikes, pH swings. This is why nano tanks are not recommended for complete beginners. The key to nano tank success is stability: stable temperature, stable parameters, consistent maintenance.
Choosing the Right Tank
All-in-one nano tanks (with built-in filter and sometimes lighting) are ideal for beginners. Look for glass construction (not acrylic), built-in filtration with replaceable media, a lid to prevent jumping fish, and a minimum of 20L. Smaller than this is very difficult to keep stable.
Equipment for Nano Tanks
Filter: an internal filter sized for 3–5x the tank volume per hour, or a small external canister. For shrimp nano tanks: a sponge filter only. Heater: a 25–50W submersible heater with a safety auto-shutoff for tanks up to 30L. Lighting: a compact LED with adjustable intensity and colour temperature.
Suitable Livestock
Fish for nano tanks
- Nano rasboras (Boraras species): tiny, schooling, stunning colours
- Chili rasboras: brilliant red, 2cm max, perfect for planted nanos
- Ember tetras: orange-red, peaceful, active schooling fish
- Pygmy corydoras: tiny bottom dwellers, need groups of 6+
- Endlers livebearers: colourful, hardy, breed readily
- Betta splendens: single male only
Invertebrates
- Neocaridina shrimp: ideal nano inhabitants, great algae cleaners
- Nerite snails: excellent algae control, 1–2 per 10L
- Amano shrimp: larger, excellent algae eaters
Avoid in nano tanks
- Any fish that grows over 4–5cm as an adult
- Goldfish (produce enormous waste for their size)
- Cichlids (most are too large or aggressive)
- Multiple male bettas (will fight)
Plants for Nano Tanks
Choose plants with appropriate scale: anubias nana 'petite', mini bucephalandra, java moss, marsilea crenata, mini hairgrass, and floating plants like salvinia or dwarf frogbit. Large swords and tall vallisneria overwhelm a 20L setup.
Water Change Schedule for Nano Tanks
Change 20–25% twice per week rather than once weekly for larger tanks. Small volumes mean faster parameter drift; more frequent, smaller changes keep things stable. Always dechlorinate and temperature-match; even a 1–2°C difference can cause osmotic shock in small volumes.
Hardscape for Nano Aquascaping
In a small tank, one focal point is enough. Choose one interesting stone or one piece of small driftwood and build your planting around it. Negative space is part of the design in nano aquascaping.
Find nano tank all-in-one setups, nano fish food, shrimp, mini plants, and aquascaping tools in our Nano & Aquatics range.
