Nano Tanks Guide (UK)

What Is a “Nano Tank”?

“Nano tank” is just hobby slang for a small aquarium. In practice, most people mean something in the 20–60L range. Anything smaller than that is possible, but less forgiving – especially for beginners.

At TinyTank Pro, we focus on 30–40L tanks as the sweet spot for UK homes: big enough to be stable, small enough to fit on a cabinet or desk.

Recommended Nano Tank Sizes

Here’s a simple way to think about nano tank sizes and what they’re best for:

• 20L: Experienced keepers, single betta or shrimp colony only.
• 30L: Great all-rounder for a betta or a small nano community.
• 40L: Best beginner size – more stable water, more stocking options.
• 50–60L: “Big nano” territory; more fish options but still compact.

If you’re new to the hobby, aim for 30–40L. It’s much easier to keep stable than a tiny cube or bowl.

Essential Equipment for a Nano Tank

No matter what you put in the tank – betta, shrimp, or small community fish – the core equipment is the same:

• Tank with lid: Stops fish jumping and reduces evaporation.
• Filter: Keeps water clear and grows beneficial bacteria.
• Heater: Keeps the temperature stable (vital in UK winters).
• Light: Lets you see the tank and grow live plants.
• Water conditioner: Makes UK tap water safe for fish.
• Test kit: Lets you see what’s happening in the water.

We’ve already put together a full review of quiet, beginner-friendly filters here: Best Nano Filters (UK).

Good Stocking Ideas for Nano Tanks

Nano tanks are not “community tanks, but smaller.” You have to be choosy. Here are some classic setups:

• Betta tank (30–40L): 1 betta, a few snails, maybe shrimp if the betta is calm.
• Shrimp tank (20–40L): Neocaridina shrimp (e.g. cherry shrimp) and snails.
• Nano community (40–60L): A small group of peaceful nano fish plus shrimp/snails.

Avoid large, messy, or hyperactive fish in nano tanks (like goldfish or big tetras). They need far more space.

Basic Setup Flow for a Nano Tank

Nearly every nano build follows the same basic pattern:

1. Choose your tank size (ideally 30–40L for beginners).
2. Pick a filter and heater sized correctly for the tank.
3. Add substrate, hardscape and plants.
4. Fill with tap water and dose water conditioner.
5. Install and run filter and heater.
6. Cycle the tank before adding fish or shrimp.

For bettas specifically, read this after: Betta Tank Setup Guide (UK).