13 Things to Know Before Getting a Goldfish

You clicked because goldfish look easy. Weve kept them for years, and we promise: a little prep makes all the difference.

Heres what actually matters so your fish thrives, not just survives.

Quick, clear, and no fluff.

1. A Bowl Is Not Big Enough

Goldfish are high-waste fish that grow large. A bowl traps ammonia and starves them of oxygen.

Start with at least 20 gallons for the first fancy goldfish, plus 10-15 gallons for each additional. Commons/comets/shubunkins need much more or a pond.

2. Filtration Is Non-Negotiable

Goldfish constantly stir up debris and produce plenty of waste. You want robust mechanical and biological filtration.

Choose a filter rated for at least double your tank volume and keep flow gentle for fancies with heavy fins.

3. You Must Cycle the Tank First

Cycling grows beneficial bacteria that convert ammonia to nitrite and then nitrate.

Use an ammonia source (fishless is kinder), test daily, and wait until ammonia and nitrite read zero and nitrate is present before adding fish.

4. They Can Live a Very Long Time

With proper care, goldfish commonly reach the teens, and some live into their twenties. The tiny feeder fish image is misleading.

Plan like you would for a small dog: space, consistent care, and backup for vacations.

5. Commons vs. Fancies Need Different Space

Common, comet, and shubunkin goldfish are streamlined, fast swimmers that thrive in large tanks or outdoor ponds.

Fancy varieties (oranda, ranchu, ryukin, telescope) are slower, bulkier, and better in spacious indoor aquariums without strong currents.

6. Overfeeding Is the Fastest Way to Trouble

Goldfish act hungry. Dont buy it. Feed small portions 1-2 times daily they finish in under a minute, then stop.

Rotate a quality sinking pellet with blanched veggies (peas with skins removed, spinach) and occasional frozen foods. Sinking foods reduce gulping air and buoyancy issues.

7. Tap Water Needs Conditioner

Most tap water contains chlorine or chloramine that harm gill tissue and your biofilter.

Use a conditioner that treats both, every time you add new water.

8. Choose Safe Substrate and Decor

Goldfish sift constantly. Fine sand or bare-bottom tanks are easiest to clean and safest.

If you prefer gravel, pick pieces too large to fit in a mouth to avoid choking or impaction. Avoid sharp decor that can tear fins or eye stalks.

9. Room-Temperature, Not Tropical

Goldfish are cold-water tolerant and do well around 65-748F.

Avoid sudden swings. Heaters arent mandatory in a stable room, but in winter a low-watt heater can prevent dips for delicate fancies.

10. Tankmates: Be Picky

Goldfish will eat anything that fits in their mouth and are clumsy swimmers.

Best companions are other goldfish of similar type and size. Avoid fin-nippers and tiny fish. If you try snails or large, peaceful species, monitor closely.

11. Weekly Maintenance Is Simple and Essential

Plan on 25-50 percent water changes weekly, vacuuming debris from the substrate.

Rinse filter media in removed tank water, not tap, to preserve bacteria. Test ammonia, nitrite, nitrate, and pH regularly.

12. Where You Buy Matters

Healthy stock saves money and heartbreak. Look for clear eyes, smooth scales, level swimming, and active foraging.

Quarantine new fish for 2-4 weeks before adding to your display to prevent parasites from wiping out your tank.

13. Budget for the Setup, Not Just the Fish

The fish is cheap; the environment isnt. Youll need a proper tank, lid, stand, strong filter, test kit, conditioner, and food.