Aquarium costs break into three parts: the tank and stand, the equipment you need to run it, and the ongoing expenses each month
A small aquarium kit—20 gallons or less—costs between $100 and $300 to set up completely. A mid-sized tank (40 to 75 gallons) runs $300 to $800. Large tanks (100+ gallons) start at $800 and climb steeply from there. These numbers include the tank itself, a stand, a filter, a heater, lighting, and substrate. Monthly costs—food, water treatments, electricity, and filter replacements—typically run $20 to $50 for a small tank and $50 to $150 for a large one. The fish themselves cost extra, anywhere from $5 to $100 per fish depending on the species.
Your actual spending depends on what kind of aquarium you want. A basic freshwater setup with hardy fish costs far less than a saltwater reef tank. Whether you buy a complete kit or assemble equipment piece by piece also changes the total. And if something breaks or you decide to upgrade later, you'll spend more.
Key Takeaways
- A complete small aquarium setup (20 gallons or less) costs $100 to $300, while a 40 to 75-gallon tank costs $300 to $800.
- Monthly expenses for a small tank average $20 to $50, covering food, filter replacements, water treatments, and electricity.
- Saltwater and reef aquariums cost significantly more than freshwater tanks because they require specialized equipment and more frequent maintenance.
- Buying a complete kit is usually cheaper upfront than purchasing equipment separately, but kits often include lower-quality filters and heaters.
- Fish prices vary widely by species, from $5 for common goldfish to $50 to $100 for specialty fish like discus or marine species.
Breaking down the initial setup cost
The tank itself is the foundation. A 20-gallon glass aquarium costs $40 to $80 new. A 55-gallon tank runs $80 to $150. Larger tanks cost more per gallon as they get bigger. Acrylic tanks are lighter and more durable but cost 20 to 40 percent more than glass.
A stand designed for your tank size costs $50 to $200. You can use a sturdy table or dresser instead, but a proper stand distributes the weight safely—a 55-gallon tank filled with water weighs over 400 pounds. A filter rated for your tank size costs $30 to $150 depending on type (hang-on-back filters are cheapest; canister filters cost more but work better for larger tanks). A heater for a small tank costs $15 to $40; larger tanks need more powerful heaters at $40 to $100. Lighting runs $20 to $80 for basic LED strips; specialty lighting for planted tanks or reef tanks costs $100 to $300. Substrate (gravel, sand, or soil) costs $10 to $40 per bag, and you'll need 1 to 3 bags depending on tank size.
Complete kit pricing versus buying separately
An all-in-one aquarium kit bundles the tank, stand, filter, heater, and lighting together. A 20-gallon kit costs $120 to $250. A 40-gallon kit runs $250 to $500. These kits save money upfront—you pay 15 to 25 percent less than buying each piece separately—but the included equipment is often lower quality. The filter may be weak, the heater may heat unevenly, and the lighting may not be bright enough for live plants.
Buying equipment separately costs more initially but lets you choose better-quality pieces. A quality filter, heater, and light for a 40-gallon tank might cost $200 to $300 total, compared to $100 to $150 in a kit. Over time, better equipment breaks down less often and performs better, so the extra cost pays back through fewer replacements and healthier fish.
Freshwater versus saltwater setup costs
Freshwater aquariums are the cheapest option. A complete 40-gallon freshwater setup costs $300 to $600. Freshwater fish are hardy, filters are straightforward, and water treatments are inexpensive. Monthly costs run $20 to $40.
Saltwater aquariums cost 2 to 3 times more. A 40-gallon saltwater setup runs $800 to $1,500 because you need a protein skimmer ($100 to $300), a powerhead for water circulation ($30 to $100), live rock ($100 to $200), and specialized salt mix ($20 to $40 per month). Reef tanks—which keep corals—cost even more. A 40-gallon reef setup starts at $1,200 and easily reaches $2,000 or more. Reef lighting alone costs $150 to $400. Monthly costs for saltwater tanks run $50 to $100; reef tanks run $75 to $150 monthly.
Monthly operating and maintenance costs
Food costs $5 to $15 per month for a small tank. Filter cartridges or media need replacing every 4 to 8 weeks at $10 to $30 per replacement. Water treatments—dechlorinator, pH adjusters, beneficial bacteria—cost $10 to $20 per month. Electricity to run the heater, filter, and lights costs $5 to $20 monthly depending on tank size and your local power rates. If you have a saltwater tank, salt mix adds $20 to $40 monthly.
Unexpected costs happen. A heater fails and needs replacing ($30 to $100). A fish gets sick and you buy medication ($15 to $40). You decide to upgrade your filter ($50 to $200). Budget an extra $100 to $200 per year for these surprises, or $8 to $17 monthly.
Fish and live plant costs
Common freshwater fish—tetras, guppies, danios, corydoras catfish—cost $2 to $8 each. Goldfish cost $3 to $15. Specialty freshwater fish like discus, angelfish, or plecos cost $10 to $50. Saltwater fish are much pricier: clownfish cost $15 to $30, tangs cost $30 to $80, and rare species can exceed $100.
Live plants for freshwater tanks cost $5 to $20 per plant. A planted 40-gallon tank might have 15 to 25 plants, so budget $75 to $500 for plants alone. Live rock for saltwater tanks costs $3 to $8 per pound; a 40-gallon reef tank needs 40 to 60 pounds, so $120 to $480 for rock. Corals for reef tanks cost $20 to $100 each, and a reef tank typically has 10 to 20 corals.
Cost comparison table for common setups
| Setup Type | Tank Size | Initial Cost | Monthly Cost |
|---|---|---|---|
| Basic freshwater kit | 20 gallons | $120–$250 | $20–$30 |
| Freshwater with quality equipment | 40 gallons | $400–$600 | $30–$50 |
| Planted freshwater | 40 gallons | $500–$800 | $40–$60 |
| Saltwater fish-only | 40 gallons | $800–$1,200 | $60–$100 |
| Saltwater reef | 40 gallons | $1,200–$2,000 | $100–$150 |
Ways to reduce aquarium costs
Buy a used tank and stand. Used aquariums cost 30 to 50 percent less than new ones. Check for cracks or leaks by filling it with water in the seller's driveway before you buy. Used filters and heaters are safe to buy if they work, but replace the filter media before using it.
Start with a smaller tank. A 20-gallon tank costs half as much as a 40-gallon and takes up less space. You can always upgrade later. Choose hardy fish species that don't need expensive equipment—goldfish, tetras, and corydoras are cheap and forgiving. Avoid specialty fish and reef tanks if you're on a tight budget.
Buy equipment on sale. Aquarium stores run promotions around holidays. Online retailers often undercut local stores by 10 to 20 percent. Join aquarium clubs or online forums where hobbyists sell used equipment at steep discounts. Propagate your own plants instead of buying new ones—most aquatic plants grow quickly and can be divided.
Frequently Asked Questions
Is a 10-gallon aquarium cheaper to run than a 20-gallon?
Yes, but not by much. A 10-gallon tank costs $80 to $150 to set up and $15 to $25 monthly. The savings are only $30 to $40 per month compared to a 20-gallon. A 10-gallon tank is also harder to maintain because water quality changes faster with fewer gallons, so fish are more likely to get sick. Most experts recommend starting with at least 20 gallons.
How much does it cost to keep an aquarium running if I don't change anything?
Electricity and food are your main costs. A small aquarium uses about 30 to 50 watts of power, costing roughly $3 to $6 monthly depending on your local electricity rates. Food costs $5 to $15 monthly. Filter cartridges and water treatments add $15 to $30 monthly. So a small tank costs $25 to $50 monthly if nothing breaks.
Can I use a regular table instead of an aquarium stand?
Only if it's very sturdy. A 40-gallon tank filled with water weighs over 400 pounds. A flimsy table will sag or collapse, spilling water and killing fish. Use a table rated for at least 500 pounds, or buy a proper stand designed for aquariums. A stand costs $50 to $200 but is built to handle the weight safely.
What's the cheapest way to start an aquarium?
Buy a used 20-gallon kit for $60 to $120, add hardy fish like goldfish or tetras at $2 to $5 each, and spend $20 to $30 monthly on food and filter replacements. Your total first-year cost would be around $300 to $400. Avoid saltwater and reef tanks, specialty fish, and live plants until you're comfortable with the hobby.
Do I need to spend more money if I want a planted aquarium?
Yes. Live plants need stronger lighting ($50 to $150 instead of $20 to $40) and nutrient-rich substrate ($30 to $60 instead of $10 to $20). Plants themselves cost $75 to $500 depending on how many you want. Monthly fertilizer costs $5 to $15. A planted 40-gallon tank costs $200 to $400 more to set up than a non-planted tank.