Beginners Be Aware Before Buying Your Fish Tank – Size Matters

On the off chance that you are thinking to set up an aquarium, one significant thought is the fish tank size. The wrong size tank often leads to a great deal of problems.

In general, you either buy a tank first and afterwards look into which fish to purchase or decide on the fish you want to keep and then pick the right tank size to suit.  It may be that the size of the tank is determined by the space you have available for it to stand or fit into.  Then the selection of fish must be right for the tank size you are fixed with using.

Should I purchase a fish tank or the fish first?

One of the main reasons individuals choose to have an aquarium is because they really like a particular fish in which case you ought to choose the tank size depending on the breed requirements. If you aren’t too specific about the type of fish, you can buy your preferred fish tank and then continue with the selection of fish that work for that particular tank size.

So why should beginners buy bigger fish tanks:

Many fish thrive better in larger tanks with more swimming space. When there isn’t enough room to swim, some fish get stressed and this can lead to them developing a weak immune system.  Certain fish will start to show behavioral issues in smaller tanks.

Commonly people find it easier to maintain the water temperature and the right chemistry with larger tanks.  Certainly, as a beginner you should always avoid fish bowls and really small tanks.  A 30 gallon fish tank is an ideal choice.

Many fish owners are opting for acrylic tanks because of their aesthetic stylish appeal, durability and lightweight. If you are feeling a little overwhelmed by the choices of fish tank available, check out our selection here.

Common problems with small aquariums:

  • Unstable water parameters: With less water there occurs fluctuation in water pH and temperature which harms fish.
  • Quick build-up of ammonia: Fish produce ammonia constantly and the ammonia level spikes up sooner in a small tank even if the filter system is efficient. This makes it tough to maintain a healthy aquarium.
  • Less oxygen: Since there is limited water surface, there isn’t sufficient room for gas exchange between water and atmosphere thus resulting in less oxygen for fish.
  • Stunted fish growth: Some fish like goldfish continue to grow, see our article about them for more details. In small tanks the growth of such fish and others becomes stunted thus causing damage to their health.

Issues that are overlooked by many fish owners when choosing fish tank size:

  • Mandatory minimum placement of school fish: There are some fish like Rasboras, Tetra, Corydoras which fall under the category of school fish. The school species generally has to be placed together as a group of a minimum 5 for them to thrive healthy and exhibit normal behaviors. If you want to purchase any of these fishes, do the math and choose an appropriate fish tank size.
  • Failing to take into account fish tank dimensions: Some fish like angel fish have peculiar shape. They need taller tanks. Similarly, some fishes like to swim high in which case you require a tall tank.  To get a better understanding of how different fish react and what they want read our article about Barbs to get you started in your research.

The tank size should be above the bare minimum requirement. Do your homework on the web.  Read about the fish tank requirements for the fish species you are keen on and then buy the right tank for them to thrive.

If you know the aquarium dimensions input them into our aquarium calculator here to confirm the size of the tank – so you know how much water it will hold, this will help you work out the fish types and filter sizes etc.


12 thoughts on “Beginners Be Aware Before Buying Your Fish Tank – Size Matters”

  1. I got the biggest fish tank that I could afford at the time when I went to get my first setup. It was an awesome 75 gal tank.

  2. It would be so annoying to mess with trying to clean up the ammonia build up, etc. that occurs in the small tanks. I don’t get the point of them really, perhaps for novelty appeal? Or ease? but to me it’s easier to maintain a larger tank.

  3. Our son loves his 30 gallon tank in his room, but it’s just for him to have a few fish, he has a few guppies. He has enjoyed it a lot.

  4. My girlfriend got me a nano fish tank over 10 years ago. I loved it, but soon realized this thing was tiny. That’s when I bought a bigger tank, and the rest is history!

    • omg I used to have one of those when I didn’t know s*** about fish. I am shocked my beta lived as long as he did in one of those tiny things. They need to take them off the market imo.

  5. Have you seen those tiny waterfall fish bowls on Amazon? They are terrible! Should not be allowed to sell these small things.

  6. Yeah I’d def plan it all out like what kind of fish you are getting before you settle on a tank…. made the mistake of getting a tank first and deciding on the fish later and then I was limited on what kind of fish I could get.

  7. We had a nano tank for one beta. The beta seems content in it. But I wouldn’t keep other fish in it. I wanted to start a coral tank at some point. Any recommendations for starting size?


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