How much does it cost to keep a betta fish?

Almost all of the cost is the initial setup, which is a one-off. After that the recurring costs are food, water conditioner, test kit refills and electricity for the heater, and those are modest. The single biggest saving available is buying an adequate tank once instead of a small one twice.

Why does this article not give a total?

Because we would have to invent it. Prices differ by country, retailer, currency and year, and electricity tariffs vary enormously between regions. A confident-looking total would be a fabricated statistic, so instead this page gives you the complete shopping list and the arithmetic to price it where you live.

What is the biggest ongoing cost?

Electricity for the heater, in most cases. It is also the one you can calculate precisely: heater wattage times hours running divided by 1000 gives kilowatt hours, multiplied by your tariff. A heater cycles on and off rather than running constantly, so the real figure is well below the maximum.

Is a betta a cheap pet?

Compared with a dog or a cat, yes, and the ongoing cost is genuinely low. It is not free, and the cheap version sold in shops, meaning a bowl and a tub of flakes, produces a short-lived fish and repeat purchases.

Where do people waste money on a betta setup?

Buying a tank under five gallons and replacing it, buying a preset heater that cannot be adjusted and replacing it, buying test strips and then buying a liquid kit anyway, and buying decorative ornaments instead of plants. Each is a purchase made twice.

Betta care basics

What a Betta Actually Costs: Setup and Yearly Running Costs

The full list of what you buy once, what you buy again, and how to work out your own running cost instead of trusting an invented total.

By Bun BerkaPublished August 10, 20264 min read

A diagram with one large cluster of equipment icons and one small cluster of consumable icons — One-off purchases against recurring onesSchematic diagram separating one-off purchases from recurring ones by group size. No prices, totals or brands are shown.

The fish costs a few dollars. Everything else is the actual expense, and it is mostly paid once.

This page gives you the complete list and the arithmetic. It does not give you a total, and the reason is in the next section.

Why there is no total on this page

We would have to make it up.

Prices differ by country, retailer, currency and year, and electricity tariffs differ by an order of magnitude between regions. A figure like “about ninety dollars a year” reads as researched and would be nothing of the sort. Inventing statistics is the one thing this site will not do, even where a number would be more satisfying than a method.

So below is the full shopping list, the recurring items, and a calculation you can run against your own bills. Fill it in once and you will have a real number instead of somebody else’s guess.

What you buy once

Item	Notes
Tank, 5 gallons minimum	The largest single cost, and the one worth not economising on
Adjustable heater	Adjustable, not preset. Sized to the volume
Thermometer	Separate from the heater
Sponge filter, plus a small air pump	Cheap, quiet, and the bacteria live in it
Lid	Often included. Buy or cut one if not
Substrate	Sand or fine gravel
Live plants	Anubias and java fern last years
Liquid test kit	Runs several hundred tests
Siphon and bucket	Dedicated to the tank
Net	Dedicated to the tank
The fish	The smallest line on this list

What you buy again

Item	Roughly how often
Pellet food	A small tub lasts a single betta many months
Water conditioner	Depends on water change volume. A bottle lasts a long time
Test kit refills	When a reagent bottle empties
Filter sponge	Rarely. Rinse it in tank water, replace only when falling apart
Frozen treats	Optional
Electricity	Continuous, see below
Replacement heater	Heaters fail eventually. Budget for one every few years

That last row is the one people forget. A heater is a consumable on a multi-year cycle, and the failure mode that matters is a heater stuck on.

Calculating your electricity cost exactly

This is the one number you can work out precisely rather than estimate.

kWh per day  = (heater watts × hours running per day) ÷ 1000
cost per day = kWh per day × your tariff per kWh
cost per year = cost per day × 365

Two notes that keep the answer honest.

A heater does not run continuously. It cycles on to hold temperature and off again, and the proportion depends on how cold the room is. Using the full 24 hours gives you a worst case, not a typical case. If you want a realistic figure, a plug-in energy meter measures the actual draw over a week.

Add the air pump for the sponge filter and the light. Both are small, and both are easy to leave out and then wonder why the total looks low.

Your tariff per kWh is on your electricity bill. Use that, not a national average.

Where the money actually gets wasted

Four purchases made twice, in order of how often it happens.

A tank under five gallons. It gets replaced, either because the fish struggles or because the owner learns better. Buying ten gallons first is cheaper than buying three then ten.

A preset heater. Cannot be adjusted, frequently sits at the wrong temperature, and gets replaced by an adjustable one.

Test strips. Bought for convenience, found unreadable at low ammonia, replaced by a liquid kit. Buy the liquid kit.

Plastic ornaments. Bought for looks, tear the fins, replaced with silk or live plants. Buy plants.

The cheap version that is not cheap

A cup fish, a bowl and a tub of generic flakes is the lowest price at the till and the highest cost over time, because the fish does not last. A cycled, heated five gallon is a modest one-off outlay that produces a fish living out its actual lifespan.

That is the entire economic argument, and it happens to be the welfare argument as well.

Where to go next

The tank size guide covers why five gallons is the floor. The tested tanks guide covers what to look for in a specific purchase, and the bowl article covers why the cheapest option on the shelf is the expensive one.

Key takeaways

The fish is the cheapest part of owning a fish. Almost all the cost is the setup.
Setup is one-off. Running costs are small and dominated by electricity for the heater.
We do not print a total, because a made-up figure is worse than no figure. The worksheet below gives you a real one.
Electricity is the one cost you can calculate exactly: watts, hours and your own tariff.
The cheapest mistake to avoid is buying twice. An undersized tank gets replaced.

Frequently asked questions

How much does it cost to keep a betta fish?: Almost all of the cost is the initial setup, which is a one-off. After that the recurring costs are food, water conditioner, test kit refills and electricity for the heater, and those are modest. The single biggest saving available is buying an adequate tank once instead of a small one twice.
Why does this article not give a total?: Because we would have to invent it. Prices differ by country, retailer, currency and year, and electricity tariffs vary enormously between regions. A confident-looking total would be a fabricated statistic, so instead this page gives you the complete shopping list and the arithmetic to price it where you live.
What is the biggest ongoing cost?: Electricity for the heater, in most cases. It is also the one you can calculate precisely: heater wattage times hours running divided by 1000 gives kilowatt hours, multiplied by your tariff. A heater cycles on and off rather than running constantly, so the real figure is well below the maximum.
Is a betta a cheap pet?: Compared with a dog or a cat, yes, and the ongoing cost is genuinely low. It is not free, and the cheap version sold in shops, meaning a bowl and a tub of flakes, produces a short-lived fish and repeat purchases.
Where do people waste money on a betta setup?: Buying a tank under five gallons and replacing it, buying a preset heater that cannot be adjusted and replacing it, buying test strips and then buying a liquid kit anyway, and buying decorative ornaments instead of plants. Each is a purchase made twice.