Nano Tank Supplies — Aquarium Equipment

The supplies you need for a nano tank depend on whether you are setting up a freshwater planted nano, a saltwater fish-only nano, or a nano reef. Each has a different core list, but all three share the same foundation: a reliable filter, heater, thermometer, and water test kit. Get those right, and the rest is customization. Skip them or buy the cheapest versions, and you will spend more money fixing problems than you saved upfront.

This guide covers the full supply list for each nano tank type, gives you specific product names and sizing, and tells you what is worth the money versus what you can skip or buy cheaply.

What Counts as a Nano Tank

There is no universal definition, but in practice:

Freshwater nano: 2.5 to 20 gallons
Saltwater nano: 10 to 30 gallons (smaller is possible but challenging)
Nano reef: 10 to 30 gallons with live corals

The smaller the tank, the faster parameters shift. A small bioload event (a single dead shrimp, an overfed day) that would barely register in a 75-gallon tank can spike ammonia in a 10-gallon nano within 12 hours. Stability is the goal of every supply decision you make for a nano.

Core Supplies for Every Nano Tank

Filtration

In a nano tank, you have less room for equipment than in a larger system, so choosing the right filter style matters.

For freshwater nanos (2.5 to 10 gallons): A sponge filter powered by a small air pump is the most reliable and tank-space-efficient option. The Aquatop SP-1 or the Hikari Bacto-Surge sponge filter runs on the Tetra Whisper 10 air pump and provides solid biological filtration without taking up space inside the tank. Total cost: $12 to $18 for pump and sponge filter combined.

For freshwater nanos (10 to 20 gallons): The Aquaclear 20 hang-on-back filter handles up to 20 gallons, is adjustable to low flow (important for shrimp and small fish), and uses replaceable foam, carbon, and ceramic media. It is reliable and the media inserts are affordable to replace.

For saltwater and reef nanos (10 to 30 gallons): An all-in-one tank (like the Innovative Marine Fusion, Red Sea Max Nano, or Waterbox Cube) with a built-in rear filtration chamber is the most practical starting point. The rear chambers handle mechanical filtration (filter floss), biological filtration (ceramic media or live rock rubble), and give you space for a protein skimmer, return pump, and heater. If you are not using an AIO tank, add a Hang-On-Back filter as your primary filter and a protein skimmer rated for the tank's size.

Heating

Nano tanks lose heat faster than larger tanks due to the higher surface-area-to-volume ratio. A heater that seems adequate at room temperature can struggle to maintain temperature in a cool room.

The Eheim Jager 50-watt submersible heater handles tanks up to 15 gallons. It is the most reliable heater in its class, with a recalibration dial and an auto shutoff when removed from water. For a 20-gallon nano, use the 75-watt version.

Never put a heater directly adjacent to your filter output in a nano. The warm outflow can fool the heater's sensor into cycling off prematurely. Position the heater on the opposite end of the tank from the filter outlet.

Thermometer

A separate thermometer is not optional. The Zacro LCD Digital Aquarium Thermometer ($10) has an external display and internal probe, so you can read the temperature at a glance without opening the tank. Check it every time you feed.

Lighting

Lighting requirements vary by what you keep, but here are the specific options by nano type:

Low-tech freshwater planted nano (5 to 15 gallons): The Finnex Stingray LED or the Nicrew ClassicLED provides enough light for low-demand plants (java fern, anubias, cryptocorynes). These cost $15 to $35 and clip onto most standard tanks.

High-tech planted nano: The Fluval Plant Nano or the Chihiros A-series give higher intensity with better spectrum control for demanding plants like carpeting species. Expect to pay $60 to $100.

Nano reef: The AI Prime 16 HD ($250) and the Kessil A160 ($200 to $250) are the standard choices for nano reef lighting. Both have app-controlled spectrum and intensity, provide adequate PAR for mixed reef corals, and fit single-tank setups without overwhelming the system.

Saltwater and Reef-Specific Supplies

Saltwater nano setups need several supplies beyond the freshwater baseline.

Refractometer

A refractometer measures salinity. Do not use a plastic swing-arm hydrometer for a reef. They are notoriously inaccurate. The Milwaukee MA887 digital refractometer ($60) is accurate, easy to calibrate, and built to last. A basic optical refractometer (any brand around $20 to $30) also works and requires calibration with a standard 35 ppt saltwater reference solution.

Target salinity for reef tanks: 1.025 to 1.026 specific gravity (33 to 35 ppt).

Protein Skimmer

A protein skimmer removes dissolved organic compounds from saltwater before they break down into ammonia. For nano reefs, the Aqua Gadget MiniMax by Innovative Marine, the Tunze Comline 9001, and the Reef Octopus ROAS 100-S are the most effective options at nano scale. All three fit in AIO rear chambers or small sumps.

The Tunze 9001 is rated for aquariums up to 26 gallons and produces consistent, dark skimmate with minimal adjustment. At $90 to $110, it is one of the better values in nano skimmers.

For more nano protein skimmer options and comparisons, the best nano protein skimmer guide covers the full category in detail.

RO/DI Water or a Supply Source

Reef tanks require purified water for mixing saltwater and for top-off. Tap water contains phosphates, silicates, and other compounds that fuel algae in a reef. Either buy purified RO/DI water from your local fish store (typically $0.35 to $0.75 per gallon) or install a small RO/DI unit.

The BRS 4-Stage Value RO/DI System handles 75 gallons per day and costs around $100. For a 20-gallon nano doing 2-gallon daily evaporation top-off plus 4-gallon weekly water changes, a basic 4-stage unit is perfectly adequate.

Auto Top-Off (ATO) System

Evaporation in a nano tank is significant. A 10-gallon nano can lose 0.5 to 1 gallon per day through evaporation. This raises salinity fast. An automatic top-off system monitors water level and adds fresh RO/DI water to compensate.

The Tunze Osmolator Nano ($90) and the Innovative Marine Hydrofill ($80) are the two most reliable nano ATO units. Both use optical or float sensors to detect low water level and trigger a small pump to add fresh water from a reservoir.

Freshwater Planted Nano-Specific Supplies

CO2 System

For demanding plants (carpeting species, stem plants), injected CO2 significantly improves growth and appearance. For a nano, a disposable CO2 cartridge system like the Fluval Mini Pressurized CO2 ($40) is an inexpensive entry point. The cartridges last 4 to 6 weeks.

A full planted nano setup with a reusable CO2 cylinder (the Up Aqua Pro CO2 regulator with a small aluminum cylinder) costs $70 to $100 upfront but provides far better control and lower long-term cost.

Fertilizers

Plants in a nano need macro and micro nutrients. Seachem Flourish Comprehensive Supplement provides trace elements and is the simplest starting point. For planted nanos with substrate, Seachem Fluorite or ADA Aquasoil as the substrate provides long-term root nutrition for heavy root feeders.

For a simple all-in-one fertilizer with macro and micro nutrients, NilocG Thrive All-In-One is a solid choice that simplifies the dosing routine.

Water Test Kit for Nano Tanks

Testing frequently is more important in a nano than in a larger tank because parameters shift faster. The API Freshwater Master Test Kit covers the four critical parameters for freshwater nanos. For nano reefs, add individual Salifert tests for alkalinity, calcium, and magnesium. Test these parameters twice weekly for the first month of a new nano reef and monthly once the system is stable.

FAQ

How much does it cost to fully set up a nano tank? A simple 10-gallon freshwater planted nano can be fully equipped for $100 to $150, not including the tank itself. A 20-gallon nano reef with all required equipment (AIO tank, skimmer, lighting, ATO, test kits, salt mix) typically costs $400 to $700 in equipment before you add live rock and livestock.

What is the minimum size for a nano reef with live coral? Ten gallons is the practical minimum for a nano reef with live coral. Smaller tanks (5 gallons or less) exist but require extremely diligent water changes and parameter management to be stable. Most hobbyists find that 15 to 20 gallons is a more forgiving starting point for a first reef.

Do I need an auto top-off for a freshwater nano? It helps but is not essential. In a freshwater nano, evaporation raises the concentration of dissolved minerals but does not affect fish health as quickly as salinity rise affects a reef. Manual top-off with fresh tap water (dechlorinated) every 2 to 3 days is manageable. For a saltwater nano, an ATO is much more important because salinity swings stress corals.

Can I use tap water in a nano reef? Only if you dechlorinate it and your tap water has very low phosphate and silicate levels. Most municipal water supplies contain enough phosphate to fuel persistent algae problems in a reef. Testing your tap water with a Hanna phosphate checker before using it is the practical approach. If phosphate is above 0.02 ppm, use RO/DI water instead.

Conclusion

Setting up a nano tank successfully comes down to buying quality in the places that matter most (filtration, heater, thermometer, test kit) and avoiding cheap substitutes in those categories. For saltwater and reef nanos, add a refractometer, a protein skimmer, and an auto top-off unit to the core list. For planted nanos, CO2 and a good fertilizer regimen make the difference between struggling plants and lush growth. The best protein skimmer for nano tank guide is a useful next step if you are fitting out a reef nano and need detailed skimmer comparisons.