Every aquarium needs a core set of supplies to keep fish alive and thriving. The basics come down to filtration, heating, lighting, substrate, water conditioners, and maintenance tools. Get those right and you have the foundation for a healthy tank. Skip any of them and you'll spend a lot of time troubleshooting sick fish and water quality problems.
This guide covers every category of tank supplies you need, from the initial setup essentials to the ongoing maintenance items that keep your aquarium running smoothly. Whether you're setting up your first 10-gallon freshwater tank or expanding an existing setup, you'll know exactly what to buy and why.
Filtration: The Most Important Piece of Equipment
Filtration is non-negotiable. Fish produce ammonia through their waste and respiration, and without a filter converting that ammonia to less harmful compounds, the water becomes toxic in days.
A good filter handles three types of filtration at once. Mechanical filtration traps particles like fish waste and uneaten food. Biological filtration uses beneficial bacteria to convert ammonia to nitrite and then to nitrate. Chemical filtration, usually activated carbon, removes dissolved impurities and odors.
Types of Filters
Hang-on-back (HOB) filters are the most common choice for freshwater tanks up to 75 gallons. Models like the Aquaclear 70 and Fluval C4 offer excellent biological filtration and easy maintenance. The Aquaclear line is particularly popular because you can customize the media inside.
Canister filters work better for larger tanks and planted aquariums. The Fluval 307 handles tanks up to 70 gallons, while the Fluval 407 works for tanks up to 100 gallons. Canisters keep all the media submerged, which improves biological efficiency.
Sponge filters are inexpensive and gentle, making them ideal for breeding tanks, fry tanks, and small aquariums under 20 gallons. They run off an air pump and cost almost nothing to maintain.
For a 40-gallon community tank, a filter rated for at least 60 gallons gives you adequate margin. The general rule is to run a filter that turns over the water volume four to five times per hour.
Heaters: Matching Temperature to Your Fish
Most tropical fish need water temperatures between 75 and 80 degrees Fahrenheit. Without a heater, tank temperatures drop to match room temperature, which causes stress and disease in tropical species.
Choosing the Right Wattage
Plan for 3 to 5 watts per gallon. A 30-gallon tank needs a 100-150 watt heater. In colder rooms or during winter months, lean toward the higher end.
The Eheim Jager TruTemp heater is widely trusted for accuracy, with a calibration dial that lets you fine-tune to within 0.5 degrees. The Fluval E Series uses a dual temperature sensor for precise control and displays current and target temperatures separately, which makes it easy to spot problems. For larger tanks, running two smaller heaters instead of one large one gives you redundancy if one fails.
Always use a separate thermometer to verify the heater is holding the correct temperature. Built-in thermostats can drift over time, and relying solely on the heater's own reading has caused many fish losses.
Lighting: More Than Just Aesthetics
Lighting affects plant growth, fish behavior, and the overall look of your tank. The type you need depends on what you're keeping.
Freshwater Community Tanks
For fish-only community tanks, basic LED lighting works well. The Nicrew ClassicLED runs about $25-35 for a 24-inch model and provides adequate light for low-light plants like java fern and anubias. Most community fish don't have strong lighting preferences, so you're mostly lighting for your own viewing.
Planted Tanks
Live plants need more intensity. Medium-tech planted tanks do well with LEDs in the 30-50 PAR range at substrate level. The Finnex Planted+ 24/7 and the Fluval Plant 3.0 are strong choices here. The Fluval Plant 3.0 connects to an app and lets you program sunrise and sunset cycles, which benefits both plants and fish.
Reef and Saltwater Tanks
Coral needs high-intensity light. Reef-capable LED fixtures like the AI Prime HD or the Kessil A160WE Tuna Blue cost $150-300 each but provide the intensity and spectrum that corals require. For deeper tanks, you may need two or more fixtures.
Substrate: What Goes on the Bottom
Substrate anchors plants, provides surface area for beneficial bacteria, and affects water chemistry.
Gravel comes in sizes from fine (1-2mm) to coarse (5-8mm). Smaller gravel traps less debris but can compact over time. Larger gravel looks natural but waste sinks between the pieces.
Aquarium sand, like Caribsea Super Naturals or National Geographic Premium Aquarium Sand, is preferred for fish like cory catfish that sift through the substrate looking for food. Sand compacts and can develop anaerobic pockets if not disturbed regularly.
Planted tank substrates like Fluval Stratum or ADA Amazonia contain nutrients that feed plant roots. These cost more (around $25-35 for a 4.4 lb bag) but make a real difference in planted setups.
For most freshwater community tanks, a 2-inch layer of medium-sized gravel or sand works well and costs $1-3 per pound.
Water Conditioners and Chemistry Supplies
Tap water contains chlorine and chloramine that will kill fish immediately. A water conditioner removes these instantly.
Seachem Prime is the most commonly recommended conditioner. A 500mL bottle treats 5,000 gallons and also detoxifies ammonia and nitrite temporarily during emergencies. At around $14 for a 500mL bottle, it's one of the best values in the hobby.
Testing Your Water
A liquid test kit is more accurate than strips. The API Master Test Kit for freshwater tests ammonia, nitrite, nitrate, and pH. This is essential during the nitrogen cycle and whenever fish show signs of stress. Strips can be off by significant margins, which matters when the difference between 0.5 ppm and 1 ppm ammonia can mean healthy fish versus dead fish.
For saltwater tanks, you'll also need to test for alkalinity, calcium, and magnesium if you're keeping coral.
Maintenance Tools: What You Use Every Week
A gravel vacuum, also called a siphon or gravel cleaner, is how you remove waste from the substrate and perform water changes. The Python No Spill Clean and Fill system connects to a faucet and makes water changes much faster. For manual siphons, the Aqueon Water Changer or a basic Lee's Siphon Kit work well for smaller tanks.
An algae scraper keeps the glass clear. For glass tanks, a magnetic scraper like the Flipper Float works well without scratching. For acrylic tanks, use only plastic-blade scrapers since metal will scratch.
A thermometer, net for catching fish, and a bucket dedicated to aquarium use round out the basic maintenance kit.
For more comprehensive recommendations, check out the Best Aquarium Supplies and Best Aquarium Equipment guides for top-rated products across every category.
Water Change Equipment
Partial water changes are the most effective way to manage nitrate buildup and keep water quality high. Most freshwater tanks need a 25-30% change weekly or a 50% change every two weeks.
The equipment you need is simple: a dedicated bucket (5 gallons is the standard), a siphon or gravel vac, and a water conditioner to treat the fresh water before it goes in.
For larger tanks, a sink-to-tank water changer like the Python system pays for itself quickly in time saved. Running a hose to the sink beats filling and hauling buckets repeatedly.
FAQ
How much do tank supplies cost to get started? A basic 20-gallon freshwater setup with filter, heater, light, substrate, and conditioners typically runs $100-200. A quality 55-gallon setup with a canister filter, accurate heater, and decent lighting usually costs $300-500 before adding fish. Reef tank setups start around $500-800 for equipment alone.
What supplies do I need for a saltwater tank versus freshwater? Saltwater tanks need everything freshwater tanks do, plus a protein skimmer, a refractometer or hydrometer to measure salinity, salt mix, and RODI water to mix with the salt. Reef tanks add a more powerful light and often a calcium reactor or two-part dosing system to maintain coral-supporting parameters.
How often do I need to replace filter media? Mechanical media like sponges and filter floss should be rinsed in old tank water every 2-4 weeks and replaced every few months. Activated carbon loses effectiveness after 4-6 weeks and needs replacement. Biological media like ceramic rings or bio-balls should never be replaced all at once since they hold the beneficial bacteria.
Can I use tap water directly in my tank? No. Tap water contains chlorine and often chloramine, which are added by water utilities to kill bacteria but will also harm fish gills. Always treat tap water with a dechlorinator like Seachem Prime before adding it to the tank.