Aquarium fish supplies fall into two categories: things your fish genuinely need to survive and thrive, and things that are nice to have but not essential. The necessities are filtration, heating for tropical species, lighting, substrate, water conditioner, and a test kit. The extras, decorations, fancy feeders, UV sterilizers, CO2 systems, come later once you understand what your specific tank actually requires.
Getting the right supplies from the start matters more than most beginners expect. Cheap equipment fails, creates unstable conditions, and ends up costing more when you replace it. This guide covers each supply category honestly, including what to look for, what to avoid, and roughly what to budget.
Filtration Supplies: The Foundation of Fish Health
A filter keeps your fish alive by processing the waste they produce every hour of every day. Fish excrete ammonia, which is toxic at even low concentrations. Beneficial bacteria in the filter convert ammonia to nitrite, and then to nitrate, which is far less harmful and removed through water changes.
Choosing the Right Filter Type
Hang-on-back (HOB) filters are the most common choice for beginner and intermediate aquarists. They hang on the back of the tank, pull water up through a tube, run it through filter media, and return it to the tank over a spillway. The Aqua Clear 70 handles tanks up to 70 gallons, has a large media compartment, and is adjustable so you can reduce flow for fish that prefer calmer water. The Seachem Tidal 55 adds a surface skimmer that removes the protein film that forms on still water.
Canister filters sit below or beside the tank and connect with intake and output tubes. They hold more media and need cleaning less often, but they cost more and are more involved to maintain. The Fluval 307 and Eheim Classic 350 are workhorses that routinely run for years without issues. These are worth the investment for tanks 40 gallons and up or for aquarists who want to minimize maintenance frequency.
Sponge filters are inexpensive, reliable, and work well in small tanks or breeding setups where gentle flow matters. A Hikari bacto-surge sponge with a small air pump handles a 10-gallon tank effectively for around $20 total.
The general rule: filter for at least your full tank volume, ideally 2-3 times. A filter rated for 30 gallons on a 30-gallon tank is running at the limit. Running it on a 20-gallon tank gives you margin.
Heating Equipment: Stability Is the Goal
Tropical fish, which includes most of the community species you'll find at a fish store, need water temperatures between 74 and 80 degrees Fahrenheit. Goldfish and some temperate species are exceptions and do fine at room temperature, but the majority of aquarium fish are from tropical environments.
A submersible heater with an adjustable thermostat is the standard. The Eheim Jager 150W is one of the most trusted heaters in the hobby, with accurate temperature control and an auto-shutoff that activates if the heater is exposed to air. The Aqueon Pro 100W uses shatterproof construction and is a reliable mid-range option. For large tanks (55 gallons and up), running two smaller heaters instead of one large one provides redundancy. If one fails, the other prevents a total temperature crash.
A standalone thermometer is worth having separate from whatever the heater displays. The API Aquarium Thermometer is a simple, inexpensive option. Heater thermostats drift over time and a verification point saves you from discovering a problem too late.
Lighting: Match the Light to the Tank
Light requirements depend almost entirely on whether you're keeping live plants and what kind.
For fish-only tanks, any decent LED strip light is sufficient. The Nicrew ClassicLED and the Aquaneat LED Aquarium Light are both affordable options that light the tank well without encouraging excessive algae growth if you keep the photoperiod to 8-10 hours per day.
For planted tanks, you need to think about PAR (photosynthetically active radiation). Low-tech planted tanks with easy species like anubias, java fern, and crypts can work under modest lighting. Demanding plants like carpeting species or stem plants that need strong growth need higher PAR lights. The Fluval Plant Spectrum 3.0 is a popular programmable option with good PAR output. The Finnex Planted+ 24/7 and the Chihiros WRGB II are two other lights that planted tank hobbyists consistently recommend.
Using a timer to automate the light cycle is a simple step that reduces algae significantly. Algae bloom when lights run too long, especially combined with excess nutrients.
Water Treatment Supplies
Tap water is treated with chlorine or chloramines to make it safe for humans. Those same chemicals are harmful to fish. You need a water conditioner to neutralize them before adding tap water to your tank.
Seachem Prime is the go-to choice. It neutralizes chlorine, chloramines, and also temporarily detoxifies ammonia and nitrite, which is useful during the cycling process. The dose is small (1 mL per 10 gallons) and a standard bottle treats an enormous amount of water. It costs about $10-$15 and is the single most cost-effective aquarium supply you'll buy.
For planted tanks, liquid fertilizers like Seachem Flourish Comprehensive or API Leaf Zone supply trace elements that plants extract from the water column. Root tabs like Seachem Flourish Tabs provide nutrients directly to substrate-rooting plants like crypts and swords.
To see options for oxygenation equipment and aeration, check the oxygen machine for fish tank price guide, which covers air pumps and related equipment across different tank sizes.
Test Kits: Your Eyes Into the Water
You cannot see ammonia, nitrite, or nitrate. You can't tell by looking at your tank whether the water is safe or building toward a crisis. A test kit is how you know.
The API Freshwater Master Test Kit contains liquid reagents for pH, ammonia, nitrite, and nitrate. It runs around $25-$35 and includes enough reagent for approximately 800 tests. Liquid test kits are significantly more accurate than dip strips, which give rough approximations at best. When you're troubleshooting sick fish or monitoring a new tank cycling, accuracy matters.
Test weekly for the first month of a new tank's life. After that, every two weeks is sufficient for an established, stable tank. Test any time fish start acting strangely, sitting at the bottom, gasping at the surface, or showing clamped fins.
Maintenance Tools: The Supplies You'll Use Every Week
Water changes are the most effective way to maintain water quality. Regular water changes remove accumulated nitrate and replenish trace minerals.
For water changes, you need a gravel vacuum (siphon) to pull debris out of the substrate while draining water. The Python No Spill Clean and Fill connects to your faucet and makes changes faster and less messy in large tanks. For smaller setups, the Lee's Pro-Series gravel vac and a couple of buckets work fine.
An algae magnet or scraper keeps the glass clean. The Fluval Edge Magnetic Scraper and the Flipper Float Scraper both work well, and the Flipper has a dual-sided design that switches between soft and hard blades for different algae types.
A best online fish supply store is usually the most economical place to buy these items. Gravel vacs, algae scrapers, and nets are consistently 20-40% cheaper online than at retail pet stores.
Keep two buckets designated only for aquarium use. Soap residue is lethal to fish, and any bucket that's held cleaning chemicals should never touch your tank water.
Fish Food: Quality and Variety
What you feed your fish directly affects their color, immune function, and overall health. Low-quality foods with fillers as the primary ingredient provide less nutrition per dollar than high-quality options.
Flake foods work for most community fish. Omega One Freshwater Flakes and New Life Spectrum Small Fish Formula are both well-regarded options with real protein as the primary ingredient rather than fillers.
Sinking pellets are needed for bottom-dwelling fish like corydoras, loaches, and plecos, which won't compete effectively for surface food. Hikari Sinking Wafers and Hikari Crab Cuisine are popular choices.
Frozen foods like bloodworms, daphnia, and brine shrimp are excellent supplements for most fish. They provide protein and trigger natural feeding responses. Thaw in a small cup of tank water before adding to the tank to avoid temperature spikes.
Feed small amounts once or twice daily. Any food not consumed in about 2 minutes should be removed. Decomposing food is a direct source of ammonia.
FAQ
What are the most important aquarium fish supplies to buy first? The filter and heater (if keeping tropical fish) are the most important. Without reliable filtration, toxic ammonia builds up quickly. Without stable heating, tropical fish get sick. After those two, water conditioner and a test kit are the next priorities.
How long do aquarium supplies last before needing replacement? Filters and heaters can last 5-10 years with proper care. Filter media varies, sponges last indefinitely with regular rinsing, activated carbon needs replacement monthly, and specialty biological media lasts years. Test kits have expiration dates on the reagents, typically 2-3 years after opening.
Do I need a water pump in addition to a filter? Not necessarily. Most filters provide enough water movement on their own. In larger tanks or tanks with fish that prefer strong flow (like hillstream loaches or some cichlids), adding a powerhead or wavemaker creates more movement. For most community tanks, the filter alone is sufficient.
What's the minimum number of supplies needed before adding fish? At minimum: a cycled filter (with established beneficial bacteria), a heater and thermometer, a water conditioner, and a test kit showing zero ammonia and nitrite. Adding fish before the tank is cycled leads to ammonia poisoning, which is one of the most common reasons fish die shortly after purchase.
Final Thoughts
Aquarium fish supplies don't have to be complicated. Invest in a good filter, a reliable heater, and the right water treatment, then test regularly to catch problems early. The rest builds from there based on what you want to keep. Starting with quality fundamentals and adding supplies as your knowledge grows is the approach that consistently produces healthy, long-lived fish.