What to Look for When Buying a Fish Tank: Key Features to Check Before You Buy
Quick Answer
For a first aquarium, a rectangular glass tank of around 20 to 29 gallons (75 to 110 litres) on a stand built for that size is the easiest place to start. Pair it with a filter rated for the volume, add a heater if you want tropical fish, and run it empty for a few weeks before anything swims in it.
Key Takeaways
- A fully set-up aquarium weighs roughly 10 pounds per gallon once water, gravel and decor are in.
- Bigger volumes hold steadier temperature and water quality, which forgives beginner mistakes.
- Glass resists scratches and costs less; acrylic is lighter and clearer but marks easily.
- A community tank's filter should move the full volume about four to six times an hour.
- Leaks nearly always start at a silicone seam or corner, so inspect those first.
Size and Placement When Buying a Fish Tank
Start with the spot in your home rather than the tank itself. Measure the space you have, leaving a few inches behind for pipes and cables. Long, shallow shapes usually beat tall, narrow ones, because more of the surface meets the air (which helps oxygen exchange) and most fish swim side to side anyway.
| Size | Typical length | Approx. filled weight | Who it suits |
|---|---|---|---|
| 5 to 10 gallons | 16 to 20 in | 50 to 110 lb | A single betta or shrimp on a desk |
| 20 to 29 gallons | 24 to 30 in | 200 to 320 lb | First community tank |
| 40 to 55 gallons | 36 to 48 in | 450 to 620 lb | Larger groups, planted layouts |
Keep it out of direct sunlight, which feeds algae, and away from radiators.
Glass or Acrylic
This is the first real choice you make when buying a fish tank, and it mostly comes down to budget and weight.
| Feature | Glass | Acrylic |
|---|---|---|
| Price | Usually cheaper | Usually dearer |
| Empty weight | Heavier | Far lighter |
| Scratches | Resists them well | Marks easily, can be polished out |
| Clarity | Good; low-iron glass is clearer | Very clear |
| Stand needs | Can sit on edge supports | Needs full, flat support |
I'd lean towards glass for a first tank, since you'll be wiping algae off it every week or two and a stray grain of sand in the sponge won't ruin it. Acrylic earns its higher price on very large tanks, or anywhere the weight is a real worry.
What to Check Before You Pay
- Look along each seam for gaps, bubbles or lifting silicone.
- Check for chips, especially along the top edges.
- Make sure there's a lid, since many fish jump.
- Read the exact dimensions and volume rather than relying on the model name.
- Check what's included, such as filter, light and heater.
- Leak-test it with plain water in the bath or garden for a day.
Filtration, Heating and Lighting
- Filter: go a size up for goldfish or messy eaters, which need closer to eight to ten turnovers an hour.
- Heater: most tropical fish sit happily between 75 and 80°F, and a common rule of thumb is 3 to 5 watts per gallon.
- Lighting: a basic LED on a timer is plenty for fish and hardy plants.
What to Expect at Each Price
- Under $30: bowls, hanging glass and mini desktop tanks, better for decor or a few shrimp.
- $30 to $80: nano tanks and starter kits sized for a betta or a handful of tiny fish.
- $80 to $250: 20 to 40 gallon glass tanks, often the best value, though the stand is usually extra.
- $250 and up: large or rimless low-iron tanks and matching cabinets.
Safety and Setup Notes
Plan for the weight before buying a fish tank, because a filled one can damage a weak table or an old floor. Use a stand rated for that size and keep it level, since an uneven base strains the seams. Plug the electrics into a socket with a residual current device (a GFCI outlet in the US) and let each cable dip below the socket so drips fall away from the plug. New tanks need a few weeks to grow the bacteria that break down waste, and our aquarium maintenance schedule covers the weekly routine after that. If you travel often, the options in our automatic pet feeder review are worth a read.
Tanks and Filters We Stock
The Super White Glass Fish Tank Household Desk is $162.34, for anyone wanting a proper display tank.
Low-iron glass drops the green tint you see on standard glass edges, so colours look truer. It's the most serious tank we sell, and the one I'd choose if the space allows, though you'll want to plan the stand around its filled weight.
The Desktop acrylic transparent fish tank is $39.53, for a light tank on a desk or shelf.
Wipe it with a soft cloth, nothing abrasive.
The Self-cleaning Small Fish Tank – Perfect for Home Aquariums is $23.18, for a single small fish in a tight space.
It suits a betta or a few shrimp. Small volumes still need regular partial water changes, so it'll want a little attention each week.
The Mini Aquaponics Fish Tank with Clear Desktop Aquarium Growing System is $42.03, for people who like plants and fish together.
Plants grow in a tray above the water and feed on fish waste, and kids love watching both halves grow.
The Fish Tank Wet Filter Box – Easy Separation for Aquariums is $27.47, for upgrading a tank you already own.
It gives good bacteria far more room to live than most built-in filters, which makes a noticeable difference on older kits.
Where I'd Start
If you're buying a fish tank for the first time, spend more on the filter and heater than on decorations, buy the stand at the same time as the tank, and choose your fish only once the water has tested clean for a week or so. A desktop nano is lovely for one betta, but I'd keep that for a second tank once you've got the hang of things.
Frequently Asked Questions
How long should a new tank run before adding fish?
Usually four to eight weeks, until ammonia and nitrite both read zero. Adding a few hardy fish first lets the bacteria catch up.
Can a fish tank go on ordinary furniture?
Only small ones on solid, level wood, since chipboard swells when wet.
Is a rimless tank harder to keep?
Not really, though water evaporates faster and the top edges are more exposed to knocks.
Should I buy a kit or separate parts?
For someone buying a fish tank for the first time, a kit is convenient, but the bundled filter is often the weakest part and many keepers upgrade it within a year.
How long does a glass tank last?
Often ten years or more. The silicone usually fails first, so check for peeling or cloudy seams once a year.