The supplies you need to set up a fish tank are a tank, a filter, a heater, a thermometer, a light, a water conditioner, test kits, and a substrate. That's the complete foundation. Everything else, from air stones to decorations to specialized feeding tools, is either optional or something you add as your tank develops. If you have those eight things covered with quality products, your fish have what they need to thrive.
Getting too many supplies at once is a common mistake that leads to overspending on things that don't matter while sometimes missing the essentials. This guide covers what you actually need, what to look for in each category, and which products consistently deliver good results.
Filtration Supplies
Your filter is the most important piece of equipment in the tank. It runs continuously, handles the biological filtration that keeps ammonia and nitrite at zero, and mechanically removes particles from the water. A failed or undersized filter is the single most common cause of fish loss in new tanks.
Types of Filters
Hang-on-back (HOB) filters are the most popular choice for tanks from 10 to 75 gallons. The Aquaclear 50 (rated for tanks up to 50 gallons) and Aquaclear 70 are consistently recommended for their adjustable flow, large media chambers, and easy maintenance. The Seachem Tidal 55 and Tidal 75 are strong alternatives with a self-priming mechanism that makes restarts after water changes simpler.
Canister filters are better for larger tanks (75 gallons and up) or tanks with large, messy fish. The Fluval 307, 407, and 507 series are reliable and well-supported. The Eheim Classic line (2213, 2215, 2217) has a 40-year track record of reliability. Canisters hold more media volume and allow you to customize the media stack more precisely than HOB filters.
Sponge filters are appropriate for fry tanks, quarantine tanks, and breeders. They're gentle, cheap, and easy to clean. Hikari and Aquaneat make reliable sponge filters.
Filter Media
Most HOB and canister filters need three types of media: mechanical (sponge or filter floss to catch particles), biological (porous media that houses beneficial bacteria), and chemical (activated carbon to remove discoloration and odors).
Seachem Matrix and Fluval Biomax are excellent biological media. Seachem Purigen removes dissolved organics and can be regenerated with bleach and repeated soaking. Replace filter floss every 2 to 4 weeks. Rinse biological media in tank water (never tap water) to preserve bacteria during maintenance.
Heating Supplies
Most tropical fish need water temperatures between 74 and 80 F. Goldfish and some cold-water species are exceptions, doing fine without a heater in most homes.
Heater Selection
The general sizing rule is 3 to 5 watts of heater capacity per gallon of tank water. A 50-gallon tank needs a 150 to 250-watt heater. For tanks over 40 gallons, running two smaller heaters instead of one large unit is safer: if one fails open (stuck heating), the tank won't reach dangerous temperatures as quickly.
The Aqueon Pro heater line includes a thermal shutoff that cuts power if the heater runs dry, protecting it and your fish. Cobalt Aquatics Neo-Therm heaters are flat, unobtrusive, and accurate. Eheim Jager heaters are recalibrate-adjustable (you can match the setpoint to an accurate thermometer) and are popular with breeders who need precise temperature control.
Thermometers
A digital thermometer with an external display (the probe goes in the tank, the readout stays outside) is easier to read than a stick-on or in-tank glass thermometer. The $10 Zacro digital aquarium thermometer works fine. Marina makes a reliable glass thermometer for $5 if you prefer analog.
Water Treatment Supplies
Tap water contains chlorine or chloramines that are toxic to fish. Before adding tap water to your tank (for initial fill or water changes), you need to dechlorinate it.
Seachem Prime is the most commonly recommended water conditioner. It removes chlorine and chloramines, detoxifies ammonia and nitrite for 24 to 48 hours, and is highly concentrated (a few drops per gallon). A 500 mL bottle treats 5,000 gallons and costs about $12, making it extremely cost-effective.
API Stress Coat adds a slime coat protectant in addition to dechlorinating. It's worth using when transporting fish or after they've been handled.
Testing Supplies
You cannot manage water quality without testing it. The six parameters to track regularly are: ammonia, nitrite, nitrate, pH, hardness (GH), and for planted tanks, CO2 or KH (carbonate hardness).
Test Kits
API Freshwater Master Test Kit covers ammonia, nitrite, nitrate, and pH in one package for about $25. It includes enough reagents for 700+ tests and uses color matching against a card. It's accurate enough for routine maintenance.
For more precision, Salifert test kits use more refined chemistry with better resolution. Hanna Checker digital colorimeters (HI781 for nitrate, HI713 for phosphate) give numerical readouts without color matching.
Test weekly during the first three months of a new tank while the cycle establishes. Once the tank is stable (consistent 0 ammonia, 0 nitrite), monthly testing is usually sufficient unless you add new fish or notice behavioral changes.
Substrate and Decoration Supplies
Substrate (gravel or sand) serves aesthetic and functional purposes. For planted tanks, a nutrient-rich substrate like Fluval Stratum or CaribSea Eco-Complete supports root growth. For fish-only tanks, plain aquarium gravel or sand is fine.
Substrates
Rinse new gravel before adding it to the tank. Even "pre-washed" gravel releases dust that can cloud the water for days. Put it in a bucket, fill with water, stir vigorously, and drain. Repeat until the water runs clear.
Sand substrates (1 to 3 inches deep) support bottom-dwelling fish like corydoras and loaches that sift through it. Pool filter sand (50-pound bag from a hardware store, about $10) works for most freshwater tanks and is identical to expensive aquarium sand for function.
Decorations and Hardscape
Rocks, driftwood, and artificial decorations provide hiding spots that reduce stress for fish. Natural driftwood releases tannins that lower pH and soften water, which some species prefer. Malaysian driftwood and spider wood are popular choices. Rinse or boil new driftwood before adding it to prevent bacteria and mold.
Artificial plants and decorations should have no sharp edges that can tear fish fins. Look for smooth-edged silk or plastic plants rather than the stiff plastic types with hard points.
Lighting Supplies
Fish-only tanks need enough light to see your fish and support a natural day-night cycle. A simple LED hood light (Aqueon LED Aquarium Light, Fluval Flex LED) running 8 to 10 hours per day is sufficient.
Planted tanks need more, specifically light intensity matched to plant requirements. Low-tech planted tanks with easy plants (anubias, java fern, hornwort) do fine with a mid-range LED like the Finnex Stingray or Fluval Plant 3.0. High-tech tanks growing demanding carpeting plants need higher intensity fixtures like the Fluval Plant 3.0 on high or the Chihiros WRGB II.
Maintenance Supplies
Weekly maintenance keeps the tank healthy and catches problems early.
A gravel vacuum (Python No Spill Clean and Fill or a basic siphon) removes accumulated waste from the substrate during water changes. A magnetic algae scraper (Flipper Nano or Flipper Standard) cleans algae from the glass without getting your hands wet. A dedicated bucket used only for aquarium water changes prevents contamination from cleaning products.
For a comprehensive overview of where to find quality fish supplies at the best prices, our Best Online Fish Supply Store guide covers the top vendors for livestock, equipment, and dry goods. If you're also setting up aeration or adding an air pump, the oxygen machine for fish tank price article covers sizing and what to expect.
FAQ
What supplies do I absolutely need before adding fish?
Tank, filter (running and cycled), heater, thermometer, dechlorinator, and a basic test kit. Fish can go in once ammonia and nitrite read zero. You don't need decorations, special lighting, or anything else before the first fish.
How much should I budget for a basic fish tank setup?
A 20-gallon freshwater tank with a quality HOB filter, heater, thermometer, light, and test kit runs about $150 to $250 depending on brand choices. Fish add $20 to $100 depending on species. Substrate, decorations, and plants add another $20 to $60.
Do I need an air pump for my fish tank?
Not always. A properly sized filter provides surface agitation that aerates the water. Air pumps with air stones are useful for tanks with very large fish loads, hospital tanks, or species that prefer high oxygen levels (rainbow fish, white cloud minnows). They're also useful as a backup circulation source during power outages if you have a battery-powered air pump.
How long should I run the light each day?
8 to 10 hours is the standard recommendation for fish-only tanks. For planted tanks, 8 hours is a good starting point to avoid algae problems. Using a timer (a simple mechanical timer costs $5 to $10) ensures a consistent photoperiod, which benefits both fish and plants.
The Supply Priority Order
Start with what keeps your fish alive: filter, heater, water conditioner, and test kits. Then add what makes the tank comfortable: substrate, a light, and a few hiding spots. The rest fills in as you learn what your specific fish need. The supplies listed above cover 95 percent of situations without requiring premium options in every category.