The supplies every pet fish owner needs fall into five main categories: a tank with filtration and heating, proper substrate and decor, water treatment chemicals, feeding equipment, and maintenance tools. The exact items depend on whether you're keeping freshwater or saltwater fish, but the core list is consistent across most setups.
Knowing what to buy upfront saves money and keeps fish healthier from day one. Buying the wrong size filter, skipping a water conditioner, or underestimating the importance of a heater are the most common beginner mistakes, and they're avoidable. This guide covers every category with specific product examples and honest guidance on where to spend money versus where you can save.
The Tank and Stand
The tank is the obvious starting point. Sizes range from 2.5 gallons (too small for most fish to be honest) up to several hundred gallons. For beginners, 20-29 gallons is the sweet spot: large enough to maintain stable water parameters, small enough to be manageable.
Glass vs. Acrylic
Glass tanks are heavier but resist scratching better and are cheaper. Acrylic is lighter and clearer but scratches easily. For most freshwater setups, glass is the practical choice.
Standard tank kits like the Aqueon Starter Kit, Fluval Flex, or Marineland Portrait include the tank, a basic filter, heater, and sometimes a light. These kits run $50-150 and make sense for beginners who don't want to piece together every component.
Stands
A filled 40-gallon tank weighs roughly 450 pounds. Standard furniture doesn't hold that safely. Use a purpose-built aquarium stand or a piece of solid furniture rated for the weight. Aqueon and Marineland both make metal and wood stand options sized to match their tanks.
Filtration: The Core Life Support
Filtration converts toxic fish waste (ammonia) into less harmful compounds through the nitrogen cycle. Without a filter running beneficial bacteria, most tanks become dangerous within 48-72 hours of stocking.
Choosing a Filter Type
Hang-on-back filters work for tanks up to 75 gallons and are the easiest to maintain. The Aquaclear 50 handles tanks up to 50 gallons and has one of the best filtration-to-price ratios in the hobby at around $45. The Seachem Tidal series (Tidal 35, Tidal 55, Tidal 75) adds a surface skimmer feature and is another strong option.
For larger tanks, canister filters like the Fluval 307 or Eheim Classic 250 provide higher filtration capacity and run more quietly. Canister filters are sealed, so they don't sit on the rim of the tank and are less visible.
Internal filters work well for small tanks and hospital tanks. The Aqueon QuietFlow Internal Filter is a common choice for tanks under 10 gallons.
Size the filter to the tank volume, not the fish count. A filter rated for "up to 50 gallons" on a 50-gallon tank is undersized when you account for fish bio-load. Aim for a filter rated 25-50% above your actual tank volume.
Heating and Temperature Control
Tropical fish (which includes most of the commonly sold freshwater species) need temperatures between 72 and 80 degrees Fahrenheit. Room temperature in most homes runs 65-72 degrees, which is too cold.
Submersible heaters are the standard. The Fluval E Series heaters display both current and target temperature using dual sensors, which makes them easy to monitor. They come in 50, 100, 150, and 200 watt versions. Use 3-5 watts per gallon as a starting point: a 30-gallon tank needs a 100-150 watt heater.
The Eheim Jager is a trusted alternative at a lower price point. It's fully submersible and has a calibration dial for fine-tuning.
Run a separate digital thermometer to verify your heater is maintaining the right temperature. An incorrect heater dial setting or a failing thermostat can cause temperature swings that stress or kill fish.
Lighting
Light requirements depend entirely on what you're keeping.
Fish-Only Tanks
Basic LED lighting works fine. Fish don't have strong lighting requirements, so you're lighting for your own viewing. The Nicrew ClassicLED in the appropriate size for your tank costs $20-35 and runs 10-14 hours per day on a timer. An outlet timer for lighting ($10-15) automates this completely.
Planted Tanks
Live plants need more intensity. Low-light plants like java fern, anubias, and cryptocorynes grow under basic LED lighting. Medium-light plants like swords and most stem plants need 30-50 PAR at the substrate. High-light plants like carpeting species need 50+ PAR.
For a planted 20 or 29 gallon, the Finnex Planted+ 24/7 and the Fluval Plant 3.0 are well-regarded mid-range options.
Water Treatment and Testing
Tap water contains chlorine and chloramine. Both will damage fish gills and kill beneficial bacteria. Dechlorinate every drop of tap water before it enters the tank.
Seachem Prime is the go-to conditioner for most aquarists. It detoxifies ammonia and nitrite temporarily in addition to removing chlorine, which is useful during the nitrogen cycle when parameters can spike. A 500mL bottle treats 5,000 gallons and costs around $14.
Test Kits
Testing your water is the only way to catch problems before fish die. The API Freshwater Master Test Kit tests pH, ammonia, nitrite, and nitrate. It costs about $30 and includes enough reagent for 800 tests. Liquid test kits are more accurate than paper strips.
Test weekly during the first month of a new tank's life. Once the tank is established and parameters are stable, monthly testing is usually sufficient unless fish show signs of stress.
For a broader overview of the best places to source supplies, check out the Best Online Fish Supply Store guide. For aeration needs, see oxygen machine for fish tank price options.
Substrate and Decor
Substrate is the material covering the tank floor. It affects water chemistry, plant health, and fish behavior.
For most freshwater community tanks, plain aquarium gravel (3-5mm grain size) works well. Caribsea Super Naturals is a popular brand with consistent sizing and natural colors. Plan for 1-2 pounds per gallon.
For fish that sift through substrate (cory catfish, loaches, many cichlids), use fine sand. Caribsea Crystal River and API Sand & Gravel are two reliable options.
Decorations provide hiding spots, which are necessary for fish health. Fish without hiding spots experience chronic stress, which suppresses their immune systems and makes them susceptible to disease. At minimum, include enough decorations that all tank inhabitants can retreat from open water when they choose to.
Food and Feeding Tools
Match food type to fish type. Flake food is the standard for community fish but not all fish eat at the surface where flakes float. Bottom dwellers like catfish and loaches need sinking pellets or wafers. Larger cichlids and predatory fish need appropriately sized pellets or frozen food.
Specific Food Recommendations
Northfin Community Formula flakes hold water quality better than many brands because they produce less waste. New Life Spectrum pellets in various sizes cover community fish, cichlids, and carnivores. Hikari Sinking Wafers are the standard for corydoras and plecos.
Feeding tools are minimal: a timer and a basic auto-feeder if you travel. The Eheim Everyday Fish Feeder handles granules and pellets reliably and costs about $25.
Maintenance Tools
A gravel vacuum removes waste from the substrate during weekly water changes. The Python Pro-Clean in an appropriate size for your tank does this well. For larger tanks, the Python No Spill Clean and Fill connects to your sink faucet and eliminates buckets.
Algae scrapers keep the glass clear. Magnetic scrapers like the Flipper Float let you clean without getting your hands wet. Use a plastic-blade version for acrylic tanks.
A net for catching and moving fish, a dedicated aquarium bucket, and a towel you don't mind getting wet round out the basic toolkit.
FAQ
What's the minimum equipment needed to keep fish alive? At absolute minimum: a filtered tank with established beneficial bacteria, a heater for tropical species, water conditioned to remove chlorine, and species-appropriate food. You can skip the fancy lighting and decor, but filter, heat, and water quality are not optional.
How much do pet fish supplies cost upfront? A complete beginner setup for a 20-gallon freshwater tank (tank, stand, filter, heater, light, substrate, decor, conditioner, test kit, food) runs $200-350. You can spend less by buying a kit and skipping higher-end components, or more by choosing quality equipment that lasts longer.
Do I need a heater for goldfish? No. Goldfish are coldwater fish and tolerate temperatures between 60 and 75 degrees Fahrenheit comfortably. A heater would make them too warm. But goldfish need large tanks (at minimum 20 gallons for a single fish, 40 gallons for two) and strong filtration because they produce exceptional amounts of waste.
What's the first thing I should set up in a new fish tank? Get the filter running before you add fish. The nitrogen cycle that establishes beneficial bacteria takes 4-6 weeks in a new tank. Running the filter with a source of ammonia (a pinch of fish food daily, or pure ammonia) establishes the bacteria before fish go in. Adding fish to an uncycled tank causes ammonia poisoning, the most common cause of fish death in new setups.