The list of supplies your fish tank needs is shorter than most pet stores suggest. A functional aquarium requires a tank, a filter, a heater (for tropical fish), a light, a substrate, water conditioner, and a test kit. Everything else on the shelf at PetSmart falls into either "improves experience" or "waste of money" categories. Getting clear on which is which saves you real money and makes the hobby more enjoyable.
This guide covers the essential pet supplies for fish tanks, where to buy them at fair prices, which brands are worth the premium, and what you can skip entirely. Whether you're setting up your first betta tank or expanding an established freshwater community, the goal is a complete, practical supply list with specific recommendations.
Essential Supplies: The Non-Negotiables
These are the items where skimping creates real problems.
Filter
The filter is the life support system. A tank without filtration is a dying tank, period. The filter handles mechanical filtration (removing debris), biological filtration (converting toxic ammonia to safer nitrate), and optionally chemical filtration (removing dissolved organics and odors).
For a 5-10 gallon tank: the Aqueon Quietflow 10 or AquaClear 20 are both reliable. The AquaClear 20 costs slightly more ($25 vs $15) but has a media basket you can fill with custom material rather than being locked into proprietary cartridges.
For a 20-40 gallon tank: the AquaClear 50 or Marineland Penguin 200. The AquaClear handles the range better and gives you more flow adjustment.
For 55 gallons and up: a canister filter. The Fluval 307 at around $135 handles up to 70 gallons, runs quietly, and is genuinely easy to maintain. Cheaper is possible, but canister filters from no-name brands have documented reliability issues.
Heater
For tropical fish (most of what's sold at pet stores), you need water at 76-82°F. Room temperature is typically 68-72°F, which is too cold for tetras, guppies, danios, bettas, and most other common species.
The Eheim Jager TruTemp is my recommendation. The 100W version handles tanks up to 40 gallons ($25-30). The 150W handles up to 60 gallons. Eheim heaters hold temperature accurately within 0.5°F, which most cheap heaters don't.
Avoid no-name heaters from Amazon. I've seen multiple instances of cheap heaters failing and cooking tanks. At $25, the Eheim is inexpensive insurance.
Goldfish, white cloud mountain minnows, and danios can survive at room temperature (65-72°F) and don't require heaters in a temperature-controlled home.
Light
Fish need a light/dark cycle of roughly 8-12 hours of light per day. Most tank lights handle this fine. The considerations are brightness and spectrum.
For fish-only tanks without live plants, the included lights in most aquarium starter kits are adequate. For planted tanks, you need a light with output measured in PAR (photosynthetically active radiation). An Aquaticlife Planted Plus Freshwater LED ($45-65 depending on size) or Fluval 3.0 Plant Spectrum LED ($75-90) will grow most freshwater plants without CO2 injection.
Don't buy full-spectrum marine reef lights for a freshwater planted tank. They're expensive and over-engineered for the application.
Test Kit
The API Freshwater Master Test Kit is the standard. It covers pH, ammonia, nitrite, and nitrate with liquid reagent tests that are significantly more accurate than test strips. The kit tests approximately 800 times total across all parameters and costs $25-30.
Test weekly during normal operation, and daily during the first month when the tank is cycling and ammonia/nitrite levels fluctuate. There's no substitute for knowing your actual water parameters when something goes wrong with your fish.
Water Conditioner
Seachem Prime. A 250ml bottle treats 1,250 gallons and costs $10-12. It neutralizes chlorine, chloramine, heavy metals, and temporarily detoxifies ammonia and nitrite. Nothing else does all of this at comparable cost.
Important But Not Urgent Supplies
These supplies make the hobby significantly easier but aren't required from day one.
Gravel vacuum/siphon: The Python No Spill Clean and Fill attaches to your faucet, making water changes a one-person operation that takes 10 minutes rather than 30. It costs $40-55 depending on length. Before you have one, you're using buckets, which works but is tedious.
Feeding tools: Long tweezers ($8-12) for placing food exactly where you want it. Useful for target-feeding fish in community tanks where faster fish hog food before bottom dwellers get any.
Timer for lights: An outlet timer ($10-15) running your aquarium light on a consistent schedule prevents algae issues caused by irregular lighting and removes the daily task of turning the light on and off. A basic mechanical timer from a hardware store works fine.
Quarantine tank: A bare 10-gallon tank with a sponge filter and heater for isolating new fish before adding them to your main tank. A 4-week quarantine period catches most diseases before they spread. If you keep fish long-term, this pays for itself the first time you use it.
For more details on where to source these supplies at competitive prices, the Best Online Fish Supply Store guide covers the top retailers with pricing comparisons.
What You Can Skip
Aquarium salt for freshwater tanks: Marketed as beneficial for tropical freshwater fish, it's a solution looking for a problem. Most tropical freshwater fish don't benefit from salt, and plants actively dislike it. The exceptions are osmoregulation issues in livebearers and ich treatment, where it has legitimate applications. Otherwise, skip it.
Automatic fish feeders: Unless you travel frequently, these create more problems than they solve. They can jam, deliver too much or too little food, and introduce moisture into the food that causes clumping and bacteria growth.
"Beneficial bacteria" sold in bottles at big-box stores: Products like API Quick Start and Tetra SafeStart contain live bacteria that can help seed a new tank, but the bacteria often die in the bottle before use. Seachem Stability is more reliable because it contains a hardier bacterial consortium. That said, nothing replaces patience during cycling.
Color-enhancing foods as your primary food source: These are fine as a supplement, but feeding only color-enhancing foods creates nutritional gaps. Use a quality staple food (Hikari or NorthFin) and supplement with color foods occasionally.
Chemical pH adjusters: Constantly dosing pH adjusters to hit a specific number creates more instability than it solves. Most fish tolerate a pH range of 6.5-7.5 without issues. Match your fish to your tap water's natural pH rather than fighting to maintain an artificial one.
Where to Buy Fish Tank Supplies
Pet specialty stores (PetSmart, Petco): Convenient for same-day needs. Prices are typically 15-25% higher than online for equivalent products. The selection of specialty equipment and premium brands is limited.
Amazon and Chewy: Better pricing on most supplies, wider selection, and auto-ship subscriptions on consumables (water conditioner, food, filter media) save an additional 5-10%. Filters and heaters from established brands like Aqueon, Marineland, and Eheim ship without issue.
Independent aquarium stores: Best for live plants, specialty fish, advice, and brands that chain stores don't stock (Eheim, Sicce, Two Little Fishies). Worth finding your local shop for these categories specifically.
Direct from manufacturer: Some brands like Seachem sell direct at retail prices. Not typically cheaper, but useful when a specific product is out of stock elsewhere.
The Best Oxygen Machine for Fish Tank Price guide covers aeration equipment pricing if you're planning a setup with air pumps or oxygen stones.
Setting Up Your First Tank: Supply Checklist
Here's a complete list for a standard 20-gallon tropical freshwater community tank:
- 20-gallon aquarium ($25-50, or a kit)
- AquaClear 50 filter ($35-45)
- Eheim Jager 150W heater ($25-30)
- LED planted or standard light ($20-60 depending on plant goals)
- Aquarium gravel or sand (20 lbs, $15-25)
- Seachem Prime (250ml, $10)
- API Freshwater Master Test Kit ($25-30)
- Thermometer ($5-8)
- Gravel vacuum ($10-20)
- Net, 2 sizes ($5-10)
- Fish food appropriate to your species ($8-15)
Total before fish: $160-275 depending on light quality and whether you buy a full kit or individual components. Buying a kit (Aqueon Starter, Tetra Complete Aquarium Kit) runs $80-120 and includes most of this but often includes lower-quality filter and light.
FAQ
What pet supplies do I need for a betta fish? A betta needs at minimum: a tank of at least 5 gallons (bettas suffer in smaller containers), a gentle filter (bettas dislike strong current, so add a sponge or foam pre-filter to reduce flow), a heater, a light, Seachem Prime, and a quality betta food like Hikari Betta Bio-Gold. Many small betta setups use the Fluval Spec V (5 gallons) as an all-in-one that works well for a single betta.
How much should I budget for fish tank supplies? For a basic 20-gallon tropical tank, budget $160-275 for equipment before buying fish. Ongoing monthly costs for food, water conditioner, and filter media run $15-30 per month. Budget more upfront if you want live plants, which require better lighting and planted substrate.
Can I use tap water in my fish tank? Yes, with water conditioner. Add Seachem Prime at 1 capful per 10 gallons before adding water to your tank or when doing water changes. Test your tap water pH and hardness to confirm they're in a range appropriate for the fish you want to keep. Most municipal tap water is suitable for common tropical freshwater fish after conditioning.
How often do I need to replace fish tank supplies? Filter media: mechanical media (sponge, filter floss) every 4-8 weeks; biological media (ceramic rings, Matrix) never unless damaged; chemical media (activated carbon) every 4-6 weeks. Heaters: replace when they fail or show calibration drift, typically 3-5 years. Air pump diaphragms: every 1-2 years. Test kit reagents: typically good for 2-3 years from purchase.