Pet Fish Equipment

Pet fish equipment comes down to six core categories: a tank, a filter, a heater (for tropical fish), lighting, a thermometer, and water treatment chemicals. Those six things keep fish alive. Everything else, air stones, decorations, automatic feeders, test kits, is either helpful supplementary equipment or convenience. Start with the core six and add from there based on what your specific fish need.

This guide covers what each piece of equipment does, what to spend and what to skip, and which specific products work well for beginners and experienced fishkeepers alike.

The Essential Six: Core Fish Equipment

1. The Aquarium Tank

The first rule of fish tanks: bigger is more stable. A 10-gallon tank is a beginner's first choice because it's cheap and takes up little space, but it's actually harder to manage than a 20-gallon. Smaller water volumes swing in temperature and chemistry faster, which stresses fish. If you're choosing between a 10 and a 20-gallon tank for the same space, take the 20.

Standard tank sizes and their approximate costs:

• 10 gallons: $20-40 for the tank alone, or $40-70 as a starter kit
• 20 gallons (long): $30-60 tank, or $60-100 as a kit
• 29 gallons: $50-80 tank, excellent size for community fish
• 55 gallons: $80-150 tank, the "step-up" size where fish keeping gets interesting

Starter kits bundling tank, filter, and hood from brands like Marineland, Aqueon, or Tetra are convenient entry points. The Aqueon 20 Gallon Starter Kit ($80-90) includes a tank, filter, heater, thermometer, fish net, and a sample pack of water conditioner, which covers most of what you need to start.

2. The Filter

Your filter does three jobs: mechanical filtration (catching debris), biological filtration (bacteria that convert ammonia to nitrite to nitrate), and sometimes chemical filtration (activated carbon). The biological stage is the most important and the most often misunderstood.

For tanks under 30 gallons, hang-on-back (HOB) filters like the Aquaclear 20 ($30-40) or Marineland Penguin 150 ($25-35) are simple and reliable. The Aquaclear is particularly good because it uses sponge and ceramic media rather than throw-away cartridges, which lets the biological bacteria colony grow without being destroyed every time you change the cartridge.

For tanks 30-75 gallons, consider a canister filter. The Fluval 207 ($90-100) handles up to 45 gallons and provides excellent filtration with multiple media stages.

Never replace all filter media at once. This kills the beneficial bacteria colony and can crash your nitrogen cycle, leading to ammonia spikes that kill fish within days.

3. The Heater (Tropical Fish Only)

Tropical fish need stable temperatures, typically 75-80°F (24-27°C). Submersible glass heaters are the standard and most affordable option.

Size your heater at 3-5 watts per gallon. A 20-gallon tank needs a 75-100 watt heater. The Aqueon Pro Adjustable Heater (available in 50, 100, 150, and 200 watt sizes, $20-35) has a built-in thermostat with clear adjustment controls and shuts off automatically if it runs dry. The Eheim Jager is a step up in quality at $30-50 and is known for excellent temperature accuracy.

Place the heater near water flow, typically next to the filter intake, so warm water circulates evenly through the tank rather than creating hot spots.

Goldfish, white cloud mountain minnows, and some other species are "temperate" fish that don't need a heater in normal room temperatures (68-72°F). Everything tropical does.

4. Lighting

Most freshwater community fish don't have strict lighting requirements. They need a consistent light/dark cycle, roughly 8-10 hours of light per day, but intensity and spectrum matter far more for live plants than for fish.

A basic LED hood light comes with most starter kits and is adequate for fish-only tanks. The Finnex Stingray ($25-40) is a step up that provides enough intensity for low-light live plants. If you want to keep live plants like java fern, anubias, or amazon swords, the Fluval Plant Spectrum 3.0 ($60-80) gives you programmable spectrum and intensity control.

Saltwater tanks and planted freshwater tanks have more demanding lighting requirements. For those setups, lighting becomes a significant equipment investment.

5. The Thermometer

A thermometer costs $3-8 and tells you whether your heater is working correctly. It seems trivial until your heater malfunctions at 2am and your fish are in 90-degree water by morning. An LCD strip thermometer sticks to the outside of the tank and reads continuously. A submersible digital thermometer with a probe (like the Zacro LCD Digital Aquarium Thermometer, $8-10) gives more accurate readings and alarms you can set for out-of-range temperatures.

Buy a thermometer. Don't assume your heater is working.

6. Water Treatment Chemicals

Tap water contains chlorine or chloramine, which kills fish instantly. You need a dechlorinator before adding any tap water to the tank.

Seachem Prime ($8-35 depending on size) is the best all-around water conditioner. It neutralizes chlorine, chloramine, and temporarily detoxifies ammonia and nitrite in an emergency. A 500mL bottle treats approximately 5,000 gallons of water. One bottle lasts most hobbyists over a year.

API Stress Coat is another good option that also helps with fish slime coat, useful after netting or transport stress.

Secondary Equipment Worth Having

Water Test Kit

The API Freshwater Master Test Kit ($23-28) tests for ammonia, nitrite, nitrate, and pH using liquid reagents. This is far more accurate than test strips and gives you the information you need to diagnose problems early. Test weekly during the first month when your tank is cycling, then monthly after it's established.

If you're starting a new tank, a test kit is not optional. Ammonia spikes during cycling kill fish fast, and you won't know it's happening without testing.

Fish Net

A $3-5 fish net. You'll use it constantly: moving fish, removing debris, scooping out dead leaves. Buy a medium (4-6 inch) net for most community fish.

Gravel Vacuum / Siphon

A Python No Spill Clean and Fill ($30-45) or a standard Lee's Gravel Vacuum ($8-12) lets you remove water and debris from the substrate during water changes without disturbing the tank layout. Water changes of 20-30% weekly or biweekly keep nitrate under control and are one of the most impactful things you can do for fish health.

Aquarium Lid / Hood

Fish jump. Bettas especially, but tetras, danios, and many community fish will leap out of an open-top tank during sudden movements or when startled at night. An aquarium hood or a mesh lid prevents jumping losses and reduces evaporation.

For equipment comparisons and specific product recommendations across all categories, see our roundup of best online fish supply store.

Equipment for Specific Fish Types

Betta Fish Equipment

A single betta needs at minimum: a 5-gallon tank (not a bowl), a gentle sponge filter (bettas dislike strong currents), a heater, and a lid. Bettas are often sold in tiny cups at pet stores and can survive in small containers for a while, but they thrive in 5+ gallon setups with appropriate water flow.

The Fluval Spec V ($65-80) is a complete 5-gallon kit designed well for bettas. The built-in filter output can be baffled with a piece of sponge to reduce current if needed.

Goldfish Equipment

Goldfish are heavy waste producers. A single common goldfish needs a minimum of 20 gallons, with 10-15 additional gallons per additional fish. Fancy goldfish (telescope, oranda, ranchu) need at least 20 gallons each. They need strong filtration rated for at least twice their tank volume and weekly water changes.

Saltwater Fish Equipment

Saltwater aquariums require everything freshwater does plus additional equipment: a protein skimmer, live rock or ceramic biological media, a hydrometer or refractometer for measuring salinity, and a source of purified water (RO/DI water). The entry cost for a basic saltwater system is significantly higher than freshwater, typically $300-600 minimum for a modest 30-gallon setup.

For more specific equipment options and price comparisons, our guide on oxygen machine for fish tank price covers aeration equipment in detail.

FAQ

How much does it cost to set up a basic freshwater fish tank? A 20-gallon freshwater community tank with filter, heater, lighting, and basic supplies runs $100-150 for starter kit options. Add $20-30 for a water test kit and a dechlorinator. Fish cost $5-30 each depending on species. Budget $150-200 total to get started properly.

Do I need a bubbler/air stone in my fish tank? Only if your filter doesn't provide sufficient surface agitation. A hang-on-back filter that returns water to the surface agitates enough for most tanks. Add an air stone if your fish show signs of oxygen stress (surfacing, gulping at the top) or if you have a densely stocked tank with low natural water movement.

How long should I run the light on my fish tank? 8-10 hours per day is the standard recommendation. Use a $5-8 outlet timer to automate this so you're not manually switching lights and your fish get a consistent day/night cycle. Inconsistent lighting causes stress and can disrupt natural behavior.

How often do I need to do water changes? For most established tanks with moderate stocking: 20-25% water change weekly or 30% every two weeks. Heavily stocked tanks need more frequent changes. Test your nitrate level. When it consistently climbs above 20-40 ppm between changes, increase change frequency or volume.

Start Simple, Add as You Learn

Successful fish keeping starts with getting the basics right: a properly sized tank, adequate filtration, stable temperature, treated water, and a functioning nitrogen cycle. Equipment beyond that core six is valuable, but only once the foundation is solid. Buy good quality filters and heaters from the start (cheap heaters that fail overnight cause disasters), keep a test kit so you know what's happening in the water, and do your water changes consistently. The rest is refinement.