What Tank Should I Buy?

Aquariums Come in all Sizes and Shapes

There are a million types of aquariums out there. Not all of them were designed for fish. Reptiles, snakes, arachnids, and small rodents also have called an aquarium home. Also note, just because a 2-gallon combo deal fish tank at the store has a goldfish on it, that does not mean you should put a goldfish in it. That’s just packaging and marketing. They usually use the same picture for all sizes of tanks, regardless of size.

Even some prepackaged ‘made just for betta’ tanks, shouldn’t house a betta. Betta fish can technically live in anything, but that doesn’t mean they should. They deserve more.

What Size Tank?

A big question I see from people who want tanks is, what size should I get? The best recommendation I can give is, get the biggest tank you can afford to maintain but no smaller than a 5-gallon if you are going to put a fish in it. It’s worth saving up for a 10 or 20-gallon than slaving away trying to maintain a smaller size.

Bigger is Better:

My 9-gallon betta tank was a lot harder to maintain than my 30-gallon guppy tank. Small does not equal easier. Especially for a beginner, a bigger tank is more forgiving than a small one.

  • A drop of poison in a 2-gallon fish tank will kill all your fish in a breath, but a gallon of poison in the ocean isn’t noticed. The same goes for your mini-ecosystem. You have a little time to fix errors in larger tanks. Not so with small ones.
  • Small tanks will limit what you can put in. The bigger the aquarium, the better selection of inhabitants to get for it. Despite the poor goldfish being given out in bowls, goldfish get very large and need much more space, and are filthy creatures. If you can only afford a 5-gallon tank, do not get a goldfish or plecostomus. Both are very tiny and adorable to start but quickly become monster-sized.
  • More room for plants and decorations: do fish have to have them? No. But technically you don’t need your couch or TV either. Plants and decorations make fish happier. Betta fish in a vase just kind of hang out and look pretty. Betta fish in a fully planted 20-gallon aquarium are feisty little beasts that swim fast and play hard.

Have a fish picked out?

Research that fish and what it likes.

Your fish absolutely will grow as its species was intended. Whoever came up with the idea that fish only grow to the size of the aquarium was probably a shady fish dealer trying to offload junk on excited people that knew nothing about fish. Don’t fall for it.

Many aquarists go with the logic of one inch of fish per one gallon of the fish tank. By this logic, guppies that only grow to one or two inches would be ok in a 2-gallon tank. Sure, you can keep a horse in a stable forever, but it won’t be happy or healthy. It will be sick and miserable. Guppies like friends. They are schooling fish. They also like to swim, play in the current of your filter, and bread rampantly. Knowing this will help you understand why they should have a 10 to 20-gallon tank and not a two-gallon.

Search the ‘minimum size’ requirement for it and start there.

Quick note: Minimum tanks size for common fish:

  • The minimum tank size for Goldfish is 20 gallons of water per fish! They get very big and they are messy!
  • That cute little common pleco? 150 gallons! 75 is a good ‘starter’ tank. I hear they poop like Clydesdales.

Logistics: What goes where?

Once you’ve got the size picked out, time to find a place in your house to put it. Natural sunlight seems like a good idea, but can make algae flourish out of control!

A quiet, shaded spot out of drafts and the walkway is nice but make sure there is a plug handy, you’re going to need it.

For the monster-sized tanks, make sure the floor and whatever stand you put them on can hold the weight.  A 15-gallon or smaller aquarium can fit anywhere that can hold a person, but bigger tanks need better support. Embora Pets has a nice estimate on how much a tank weighs by size so you can get an idea of how things can quickly get out of hand.


When I was growing up, I had the choice of a rectangle tank or a bowl shape, but the fish world is greater than that. A 20-gallon tank can come as a corner, a bowl, a long tank, or a tall tank. It can have rounded edges or square edges or be completely round. Maybe octagon if that rocks your world or a corner tank.

Ok, what shape should I get?

Fall back on preference, but ask yourself these questions to help you decide:

  • Will it be easy to clean? Easy makes it more enjoyable and makes the chances of you cleaning it greater.
    • The tall tube aquariums from floor to ceiling look absolutely amazing, but how do you clean them? I don’t know. I have no idea.
    • I recommend you put your hand in your tank at least once a week for maintenance. Are you physically capable of getting from the top of the tank to the bottom? Will you need a ladder? Will it be safe?
    • Bowls sound great, but flat glass is easier to clean than ball-shaped glass. It worth the extra energy?
  • Are there a lot of reflective surfaces? Some fish love that. Betta fish might get stressed from constantly having to defend their territory from that weird fish that looks just like them and mimics their every move.
  • Will it fit in the area you’ve chosen?
  • What kind of stand will it need?
  • Will my chosen fish look good in it and be happy?