How Much Does a Pet Fish Cost?

Updated on September 19, 2026 | Written by Alec Pow
This article was researched using 19 sources. See our methodology and corrections policy.

A pet fish can cost less than $10, but the aquarium usually costs far more than the animal. Petco currently lists a standard male betta at $7.99, while its 10-gallon aquarium kit costs $99.99 before separate testing supplies, permanent food, fish, gravel, and decorations. The fish price is often the small line item. The habitat, water preparation, and equipment determine the real startup total.

The same pricing logic applies to community and marine aquariums. Tank volume, filtration, heat, water testing, substrate, group size, and quarantine can all add more than the livestock itself. A useful budget starts with the species and its adult housing needs, then adds the fish after the system is priced.

Article Highlights

• A current male betta listing starts at $7.99, while a 12-pack of neon tetras costs $28.99 (at $30 per hour, earning that amount would take about 58 minutes, before taxes).
• A current 10-gallon aquarium kit costs $99.99, before testing supplies, conditioner, fish, substrate, and food.
• A current 20-gallon aquarium kit costs $147.99.
• A documented betta startup subtotal reaches $157.96, with the fish representing only about 5.1% of that amount.
• A documented 20-gallon community subtotal reaches $226.96, with the fish representing about 12.8%.
• A modeled 32.5-gallon marine subtotal reaches $758.35 before a heater, stand, rock, food, and other additions.

How Much Does a Pet Fish Cost?

Freshwater livestock can be very inexpensive, but prices spread quickly by variety and selling unit. Petco’s current betta listings include specialty fish above $30 (about 1 hour of work at $30 per hour). A current 12-pack of neon tetras costs $28.99, equal to about $2.42 per fish. Those examples show why a single freshwater-fish range can hide large differences between an individual display fish and a group species sold as a pack. Package counts also change the apparent per-fish price.

Saltwater pricing should be tied to the exact species and habitat. A current aquacultured Ocellaris clownfish is listed at $17.99. The same listing calls for a 30-gallon minimum aquarium, so the livestock price cannot be separated from a much larger habitat. A $17.99 fish is not a $17.99 pet once the proper marine system is included.

Example	Fish price	Documented setup subtotal	Fish share of subtotal
Betta with 10-gallon freshwater basics	$7.99	$157.96	About 5.1%
12 neon tetras with 20-gallon freshwater basics	$28.99	$226.96	About 12.8%
Ocellaris clownfish with 32.5-gallon marine basics	$17.99	$758.35	About 2.4%

The Fish Is the Cheapest Part

The betta calculation shows how quickly habitat costs overtake livestock cost. Using the already cited $7.99 betta and $99.99 (about 3.3 hours of work at $30 per hour) 10-gallon kit, add an API freshwater test kit at $39.99 and a 4-ounce water conditioner at $9.99. The arithmetic is $7.99 + $99.99 + $39.99 + $9.99 = $157.96. The fish accounts for about 5.1% of that subtotal. This remains a partial startup total.

The community example produces the same pattern. Petco currently lists an Aqueon 20-gallon kit at $147.99. Pairing that kit with the $28.99 neon-tetra pack, the same $39.99 test kit, and the same $9.99 conditioner creates a $226.96 subtotal. The fish account for about 12.8%. Both calculations exclude substrate, food, plants, decor, shipping, tax, and extra equipment. The point is not that these are universal starter packages. It is that low livestock prices can conceal the larger cost of building a suitable home.

This same relationship appears in species-specific pages. A betta fish budget or goldfish cost makes more sense when the tank is priced before the animal.

Freshwater Setup Budget

A freshwater starter kit can bundle several expensive components. The 10-gallon Aqueon kit above includes an LED hood, power filter, preset heater, plus fish-food and water-conditioner samples. Fish, decorations, and gravel are excluded. That reduces the number of separate purchases, but it does not complete the setup. A buyer still needs water testing, permanent food, and any substrate, hiding places, plants, or extra equipment required by the chosen species.

The test-kit and conditioner inputs cited in the startup calculation add $49.98 before the owner buys substrate, food, or livestock. The test kit covers pH, high-range pH, ammonia, nitrite, and nitrate, while conditioner treats replacement tap water according to its label dose. That water-care layer is easy to miss when a starter-kit sticker price is treated as the full setup cost.

The aquarium should match the adult fish and its behavior rather than a target dollar amount. A cheap small tank can become expensive if the owner later replaces it because the chosen species needs more swimming space or a larger group.

That missing layer can alter the starting subtotal by species. Readers considering bottom-dwelling species can compare the setup implications with current catfish costs, where aquarium species vary greatly in adult size.

Saltwater Costs

Marine systems add costs that a basic freshwater setup does not need. A current retailer lists the saltwater-specific Fluval Flex 32.5-gallon aquarium at $649.99. That size clears the 30-gallon minimum stated on the Ocellaris clownfish listing cited earlier. Fluval’s saltwater model specifications confirm the 32.5-gallon marine configuration and state that the heater is sold separately.

Water preparation adds another layer. Petco lists the API saltwater master kit at $49.99 and a Fluval Sea hydrometer at $17.99. PetSmart lists a 50-gallon package of Instant Ocean sea salt at $22.39. Add the $17.99 Ocellaris and the documented subtotal becomes $758.35.

That marine subtotal still excludes a heater, stand, rock, substrate, food, backup water, shipping, tax, and optional reef equipment. The clownfish is only about 2.4% of the subtotal. The cited salt package is rated for 50 gallons, so the first purchase also leaves mix for later water preparation in this 32.5-gallon scenario. Actual use depends on target salinity and water-change volume. A reader comparing marine species can also see the broader puffer fish price range, where adult size and tank requirements can change the habitat cost sharply.

Tank Size

The old one-inch-per-gallon formula should not be treated as a stocking calculator. Aqueon describes one inch of adult fish per net gallon as a general rule of thumb and says activity, territorial behavior, available habitat, and filtration also matter. Body shape and waste production matter too. Ten inches of slender schooling fish do not create the same space and filtration problem as one bulky 10-inch fish.

Smaller tanks also change faster. The same Aqueon guidance says nitrates and other pollutants can accumulate more rapidly and reach higher concentrations in small aquariums. That is one reason the least expensive tank is not always the easiest beginner purchase. More water volume can provide greater stability, though a larger aquarium also costs more to buy, fill, heat, furnish, and support.

Group behavior adds another price multiplier. Some species should be kept with members of their own kind, while territorial species may need separation. The owner should research adult size, group needs, temperature, water chemistry, and compatibility before buying the tank. This avoids buying a small aquarium first and paying again for a larger one after the livestock choice changes.

Ongoing Monthly Costs

Electricity depends on equipment wattage, runtime, room temperature, and local utility rates. The U.S. Energy Information Administration forecasts an average residential electricity price of 18.2 cents per kWh for 2026. In an illustrative 50-watt heater scenario, continuous full-power operation for 24 hours a day over 30 days would use 36 kWh and cost about $6.55 per month. A thermostatic aquarium heater cycles, so real heater use is normally below that full-power ceiling. Filters and lights add their own consumption.

Water conditioner can be cheap per treatment even though the bottle is another startup purchase. Usage depends on the label dose and the volume of replacement tap water rather than the number of fish. Food follows a different pattern. A small freshwater aquarium may consume little food, while larger fish and marine systems can need more expensive frozen, prepared, or species-specific diets.

Filter media, replacement equipment, test reagents, salt mix, and occasional livestock losses create irregular costs that do not fit one universal monthly allowance. A better budget separates predictable electricity and food from replacement purchases that happen only when needed.

Quarantine and Health

A second tank can become part of the ownership budget when new fish are added to an established aquarium. Aquarium Co-Op recommends quarantining most new fish for four to six weeks after the last disease sign or death. That is much longer than the one-to-two-week advice found in many older aquarium guides. A temporary quarantine setup can use simple equipment, but it still needs an appropriate container or tank, filtration, heat when the species requires it, conditioner, and places for fish to shelter.

Medication should not be treated as a fixed shopping list. Parasites, bacterial disease, fungal problems, water-quality injuries, and physical trauma are different problems. Buying random antibiotics, antifungals, and antiparasitic products before identifying the problem can waste money and can complicate care. Water testing and isolation are often more useful budget items because they help reveal or contain a problem before treatment is chosen.

Fish veterinary care exists, but access varies by location and species. Large or valuable fish may justify professional diagnosis, imaging, procedures, or laboratory testing. The expense cannot be reduced to one national exam fee because fish veterinarians and services are not distributed like ordinary dog-and-cat clinics.

How to Spend the Budget

Put habitat compatibility ahead of the fish’s sticker price. A $5 fish that needs a larger group or specialized water can produce a higher total than a $25 fish that fits equipment already owned. Compare the adult animal, the required group, and the equipment needed for the whole group before checking out.

Used aquariums can cut the entry price, but inspect seams, chips, stands, heaters, and electrical equipment before relying on them. A used glass tank may be a bargain while an unknown heater or damaged stand can create a replacement cost. New starter kits can make sense when their bundled heater, filter, hood, and light match the intended species.

Makes sense if

• You choose the species before choosing the aquarium.
• The tank, filter, heater, and group size match the fish at adult size.
• You budget for testing and water preparation before buying livestock.
• You compare the full setup cost rather than the fish price alone.

Does not make sense if

• You buy a tiny aquarium only because it has the lowest sticker price.
• You use the one-inch-per-gallon rule as the only stocking test.
• You add a schooling species one fish at a time only to reduce the purchase price.
• You buy marine livestock before pricing saltwater testing and water preparation.

Verification checks

• Checked the North American fish-vet locator and confirmed that dedicated fish veterinary services exist but are geographically limited.
• Confirmed Aqueon’s nitrogen-cycle guidance says a new aquarium can take several weeks or longer to establish biological filtration and warns against adding too many fish at once.
• Cross-referenced Aqueon’s aquarium setup guidance, which says larger aquariums are more stable and advises researching animals and equipment before purchase.

Answers to Common Questions

How much does a pet fish cost?

Common freshwater fish can cost only a few dollars each, with the cited neon-tetra pack working out to about $2.42 per fish. The cited standard male betta is $7.99, while the Ocellaris clownfish example is $17.99.

How much does it cost to set up a fish tank?

The documented freshwater examples in this update total about $157.96 for a basic betta scenario and $226.96 for the 20-gallon community scenario before substrate, decor, food, tax, shipping, and other additions.

Is freshwater cheaper than saltwater?

In the documented scenarios here, yes. The freshwater examples are below $250, while the 32.5-gallon marine subtotal reaches $758.35 before several other costs.

How much does aquarium electricity cost?

A 50-watt heater running continuously at the cited 2026 national electricity price would cost about $6.55 per month. Real heater use is usually lower because thermostatic heaters cycle, while filters and lights add separate electricity use.

Do I need a quarantine tank?

A separate quarantine setup is useful when adding new fish to an established aquarium because it allows observation away from the main livestock. The cited specialist guidance recommends four to six weeks for most new fish after the last sign of disease or death.