The Real Cost Range for Starting an Aquarium

A basic aquarium setup costs between $150 and $500 for a beginner, depending on tank size and what you already own. A small 10-gallon tank with filter, heater, and stand runs roughly $150 to $250. A 20-gallon setup costs $250 to $400. If you want a 55-gallon tank with better equipment, expect $400 to $800. These numbers assume you are buying new equipment from a pet store or online retailer, not used gear from a secondhand marketplace.

The biggest variable is tank size. Larger tanks need stronger filters, more powerful heaters, and sturdier stands. A 5-gallon tank might cost $80 total; a 75-gallon tank might cost $1,200. Fish themselves are usually the smallest expense—a single betta costs $5 to $15, while fancy goldfish run $10 to $30 each. The equipment matters far more than the animals.

Key Takeaways

  • A complete beginner setup with a 10 to 20-gallon tank, filter, heater, and stand costs $150 to $400 before you buy any fish.
  • Tank size drives cost more than anything else—doubling the tank volume roughly doubles the total equipment expense.
  • Monthly maintenance costs (food, water treatments, replacement filters) typically run $15 to $40 depending on tank size and fish type.
  • Used equipment from online marketplaces or local aquarium clubs can cut startup costs in half, but inspect tanks for cracks and test filters before buying.
  • Saltwater aquariums cost two to three times more than freshwater because they need specialized equipment like protein skimmers and salt mix.

Breaking Down the Equipment Costs

The tank itself is usually 30 to 40 percent of your startup budget. A 20-gallon glass tank costs $40 to $80 new. Acrylic tanks are lighter and less likely to crack, but cost 20 to 30 percent more. A stand designed for that tank size adds $50 to $150. Cheap stands fail and tanks crack—do not skip this.

A filter rated for your tank size costs $30 to $100. Undersized filters do not work; oversized ones are fine and actually better. A heater for a 20-gallon tank costs $20 to $50. You also need an air pump ($15 to $40) if you want an air stone, a thermometer ($5 to $15), and a net ($5). Lighting varies wildly—a basic hood with incandescent bulbs costs $30 to $60, while LED systems run $80 to $200. Most beginners do not need expensive lighting unless they plan to grow live plants.

Substrate (gravel or sand) costs $10 to $30 for a 20-gallon tank. Decorations—rocks, plants, caves—range from free (if you collect your own) to $50 or more. A water testing kit to check ammonia, nitrite, and nitrate costs $20 to $35 and is not optional; you cannot see these chemicals, but they kill fish.

What Fish and Maintenance Will Cost You Monthly

Fish food costs $5 to $15 per month for a small tank. Most beginners overfeed, which wastes money and fouls the water. A small container of quality flakes lasts two to three months. If you keep live plants, fertilizer adds another $5 to $10 monthly, but plants also reduce the need for water changes.

Water conditioner to remove chlorine costs $8 to $15 per bottle and lasts several months. If your tap water is very hard or acidic, you may need pH buffers or mineral supplements ($10 to $20 per bottle, lasting months). Filter cartridges need replacing every four to eight weeks at $5 to $15 each. Some filters use sponges you can rinse instead, which saves money long-term.

Unexpected costs happen. A heater fails and costs $30 to $60 to replace. A fish gets sick and medication costs $10 to $25. A pump burns out. Budget an extra $100 to $200 in your first year for repairs and replacements. After the first year, monthly costs usually drop to $15 to $30 if nothing breaks.

Freshwater Versus Saltwater: The Cost Difference

Saltwater aquariums cost significantly more to start and maintain. A basic saltwater setup needs a protein skimmer ($80 to $300), which freshwater tanks do not. You need a refractometer to measure salinity ($20 to $50) and marine salt mix ($15 to $40 per bucket). Saltwater fish themselves cost more—a clownfish runs $15 to $40, while a freshwater goldfish costs $5 to $10.

A 20-gallon saltwater tank typically costs $600 to $1,000 to set up properly. The same freshwater tank costs $250 to $400. Monthly saltwater maintenance runs $30 to $60 because salt mix, specialized food, and additives are pricier. Saltwater is not a beginner choice unless you have experience or a patient mentor.

Where to Buy and How to Save Money

Chain pet stores like Petco and PetSmart stock standard equipment at predictable prices. Online retailers like Aqueon and Marineland often have lower prices and free shipping over a certain amount. Local aquarium clubs sometimes sell used tanks and equipment at 40 to 60 percent below retail. Facebook Marketplace and Craigslist have used setups, but inspect them carefully for cracks, rust, and working equipment before you buy.

Buying a used complete setup can cut your startup cost to $75 to $200, but you are taking a risk. Test the filter and heater before handing over money. Ask why the previous owner is selling—sometimes it is because the tank leaked or equipment failed. A new tank costs more but comes with a warranty.

Avoid starter kits sold as bundles. They often include undersized filters, cheap heaters, and poor lighting. Buying components separately costs a bit more but gives you better equipment that lasts longer.

Hidden Costs People Forget About

Electricity to run a filter, heater, and light adds $5 to $15 monthly to your power bill, depending on tank size and equipment efficiency. LED lights use less power than incandescent bulbs. A larger heater running constantly in winter costs more than a smaller one in a warm room.

If you travel or move, transporting a full tank is expensive. A professional aquarium mover charges $200 to $500. Moving it yourself risks spills and broken equipment. Some people drain and refill tanks rather than move them full, which costs time and stresses the fish.

If you decide to stop keeping fish, disposing of a large tank is not free. Some aquarium shops take used tanks for a small fee or credit toward new purchases. Recycling centers may charge $10 to $30 to take glass tanks. Plan for this possibility when you budget.

Frequently Asked Questions

Can I start an aquarium for under $100?

Yes, if you buy used equipment or start very small. A used 10-gallon tank with filter and heater from a secondhand marketplace might cost $50 to $80. Add a $10 thermometer and $5 net, and you are under $100. You will still need a water testing kit ($20 to $35) before adding fish, so your real minimum is closer to $120 to $140. Buying new equipment under $100 is nearly impossible.

Do I need to spend more money if I want colorful fish?

Colorful freshwater fish like tetras, guppies, and corydoras catfish cost $3 to $10 each and do not require special equipment. The most colorful fish are saltwater species, which require expensive tanks and equipment. If you want color on a budget, stick with freshwater and choose species known for bright patterns.

What costs the most over time—the tank or the fish?

The equipment costs the most upfront, but maintenance costs the most over time. A $300 tank lasts 10 to 20 years. Fish live two to ten years depending on species. Over five years, you might spend $900 to $1,800 on maintenance, electricity, and replacement fish, compared to $300 on the original tank. The tank is a one-time investment; everything else is ongoing.

Is it cheaper to buy a large tank or several small ones?

One large tank is cheaper than multiple small ones. A single 40-gallon tank costs less to set up than four 10-gallon tanks, and it uses one filter and heater instead of four. Large tanks are also more stable—water chemistry changes more slowly, which is better for fish. The only reason to buy multiple small tanks is if you want to keep fish species that fight each other.

Do I need to replace equipment regularly?

Filters need new cartridges every four to eight weeks, but the filter housing lasts years. Heaters typically last three to five years before failing. Air pumps last two to four years. Tanks last 10 to 20 years if you do not crack them. Most equipment fails when it fails, not on a schedule—budget for unexpected replacement costs rather than planning replacements in advance.