Aquarium costs break into three parts: the tank itself, the equipment you need to run it, and the ongoing expenses
A basic aquarium setup costs between $150 and $500 for a small freshwater tank, or $500 to $2,000 for a larger one. The price depends on tank size, whether you choose freshwater or saltwater, and what equipment comes included. A 10-gallon freshwater tank with a filter, heater, and light might run $150 to $250. A 55-gallon saltwater setup with a protein skimmer and live rock can easily exceed $1,500.
Beyond the initial purchase, you will spend money every month on food, water treatments, and electricity. Over a year, ongoing costs typically range from $200 to $600 for a small freshwater tank, or $500 to $1,500 for a saltwater system. The first year is the most expensive because you are buying equipment; after that, costs drop to mainly maintenance and replacement parts.
Key Takeaways
- A complete small freshwater aquarium (10 to 20 gallons) costs $150 to $400 to set up, while a larger freshwater tank (40 to 55 gallons) runs $300 to $800.
- Saltwater aquariums cost significantly more—$800 to $2,000 or higher—because they require a protein skimmer, live rock, and more precise equipment.
- Monthly operating costs for a small freshwater tank average $15 to $30, while saltwater tanks average $40 to $80 per month.
- The tank itself is often the cheapest part; filters, heaters, lighting, and substrate typically cost as much or more than the glass vessel.
What a basic freshwater tank costs to set up
A 10-gallon freshwater tank is the most affordable entry point. The tank itself costs $20 to $50, a basic filter runs $25 to $60, a heater is $15 to $40, and lighting is $20 to $50. Substrate (gravel or sand) costs $10 to $20, and a basic air pump or air stone adds another $10 to $15. Total: roughly $150 to $250 before you add fish or plants.
A 20-gallon tank costs more because the equipment scales up. The tank itself is $40 to $80, a better filter is $50 to $100, a heater is $20 to $50, and lighting is $30 to $80. Substrate and decorations add $20 to $40. You are looking at $200 to $400 for a complete setup. A 40-gallon or 55-gallon freshwater tank follows the same pattern: larger equipment, higher price. A 55-gallon setup typically costs $300 to $800.
What a saltwater tank costs to set up
Saltwater aquariums are more expensive because the water itself and the equipment are more specialized. A 20-gallon saltwater tank needs a protein skimmer (which removes waste), live rock (which costs $3 to $10 per pound and you need 15 to 30 pounds), and a more powerful filter. The tank, stand, and lighting alone run $200 to $400. Add a protein skimmer ($100 to $300), live rock ($75 to $300), substrate ($30 to $60), and a heater ($30 to $60), and you are at $500 to $1,200.
A 55-gallon saltwater setup is where costs climb steeply. The tank and stand are $300 to $600, lighting is $150 to $400, a protein skimmer is $150 to $500, live rock is $150 to $600, and a sump (a separate chamber that holds equipment) adds another $100 to $300. Total: $1,000 to $2,500 or more. Reef tanks with corals cost even more because corals require specialized lighting and water chemistry equipment.
Monthly and yearly operating costs
A small freshwater tank costs roughly $15 to $30 per month to run. Fish food is $5 to $10 per month, water treatments (dechlorinator, beneficial bacteria) are $3 to $8 per month, and electricity for the filter and heater is $5 to $15 per month depending on your local power rates. Over a year, that is $180 to $360. Add occasional filter replacements ($20 to $40 every three months) and you are at $200 to $500 annually.
A saltwater tank costs $40 to $80 per month. Salt mix for water changes is $15 to $30 per month, fish food is $10 to $20 per month, water treatments and additives are $10 to $20 per month, and electricity is $10 to $20 per month. Over a year, that is $500 to $1,000. Reef tanks cost more because corals need specialized food and supplements, pushing yearly costs to $1,000 to $1,500.
Hidden costs that add up
Fish themselves cost $5 to $50 each depending on the species. A small freshwater tank might hold 5 to 10 fish, so budget $25 to $200 for livestock. Saltwater fish are more expensive—$20 to $100 each—and a 55-gallon tank might hold 10 to 15 fish, so $200 to $1,500 for fish alone.
Decorations, plants, and rocks cost $20 to $100 depending on what you choose. Replacement parts—filter cartridges, heater elements, air pump diaphragms—run $10 to $50 each and wear out over time. If your heater fails or your filter breaks, you are buying a replacement when ready or your fish are at risk. A backup heater or filter costs $30 to $100 and is worth having on hand.
Water testing kits cost $20 to $50 upfront and test strips cost $10 to $20 per box. You will test your water weekly when the tank is new, then monthly once it is stable. Aquarium maintenance tools—nets, gravel vacuums, algae scrapers—cost $30 to $80 total.
How tank size affects total cost
| Tank Size | Type | Setup Cost | Monthly Cost | Year One Total |
|---|---|---|---|---|
| 10 gallons | Freshwater | $150–$250 | $15–$25 | $330–$550 |
| 20 gallons | Freshwater | $200–$400 | $20–$30 | $440–$760 |
| 55 gallons | Freshwater | $300–$800 | $25–$40 | $600–$1,280 |
| 20 gallons | Saltwater | $500–$1,200 | $40–$60 | $980–$1,920 |
| 55 gallons | Saltwater | $1,000–$2,500 | $60–$100 | $1,720–$3,700 |
Ways to reduce your first-year costs
Buy a kit instead of assembling equipment separately. Many retailers sell all-in-one kits for 10 or 20-gallon tanks that bundle the tank, filter, heater, and light for $100 to $300. These kits are cheaper than buying each piece individually, though the quality is sometimes lower than buying premium equipment separately.
Start with a smaller tank. A 10-gallon freshwater tank is easier to maintain and costs half as much as a 20-gallon. Once you understand how to keep fish, you can upgrade. Many people who buy large tanks abandon them because the maintenance is harder than expected.
Buy used equipment. Aquarium tanks, filters, and heaters hold up well over time. Used equipment on Facebook Marketplace or Craigslist often costs 30 to 50 percent less than new. Avoid used air pumps and heaters unless you can test them first, because they fail without warning.
Choose hardy, inexpensive fish. Goldfish, tetras, and guppies cost $2 to $5 each and tolerate beginner mistakes. Rare or colorful fish cost $20 to $100 and are more sensitive to water conditions. Start with hardy species and add delicate ones once your tank is stable.
Frequently Asked Questions
Is a 10-gallon tank really cheaper to run than a 20-gallon?
Yes, but not by much. A 10-gallon tank costs $15 to $25 per month and a 20-gallon costs $20 to $30 per month. The difference is mainly electricity and water treatment. However, a 10-gallon tank is harder to keep stable because water chemistry changes faster, so you may spend more on treatments or replacements if something goes wrong.
Can I save money by not using a heater?
Only if your room stays between 72 and 78 degrees year-round. Most fish need stable temperatures, and room temperature fluctuates with seasons. A heater costs $20 to $50 upfront and $5 to $10 per month to run. Without one, you risk fish stress and disease, which costs far more to treat.
Do saltwater tanks really cost three times as much as freshwater?
Yes, over the first year. A 20-gallon saltwater setup costs roughly $1,000 to $1,500 in year one, while a 20-gallon freshwater setup costs $400 to $600. The gap narrows in year two because you are no longer buying equipment, but saltwater still costs more monthly because of salt mix, additives, and more frequent water changes.
What is the cheapest way to start an aquarium?
Buy a 10-gallon kit for $100 to $150, add hardy fish like guppies or tetras for $10 to $20, and budget $20 per month for maintenance. Your first-year cost is roughly $400 to $500. This teaches you the basics without a large investment. If you lose interest, you have not spent much. If you enjoy it, upgrade to a larger tank.
Do I need to replace equipment every year?
No. A filter cartridge lasts three to six months and costs $15 to $30 to replace. A heater lasts three to five years. A tank lasts indefinitely if you do not crack it. Most equipment lasts years, so your second year costs drop to mainly food, water treatments, and occasional replacements.