What Size Fish Tank Is Best For Beginners?

I remember what it was like to get started in the fishkeeping hobby. The number of questions I had and the amount of information that I was consuming quickly became overwhelming and hard to digest.

One of the most common questions that beginner fishkeepers ask me is what size fish tank they should start with, and almost everyone is surprised by my answer.

For some reason, there is a notion that beginners should start with a smaller tank. It makes sense to start small if you are new to something, right?

Surprisingly, it’s the complete opposite.

The bigger the tank, the easier it will be to manage. Yes, it will be more expensive to purchase up front and may require more resources over time, but what you spend in money upfront will save you countless hours and bucket loads of stress in the future.

If that doesn’t make sense to you right now, don’t worry. This article will break down the benefits of starting with a larger tank as well as the disadvantages of choosing a smaller tank. Let’s jump straight in with a breakdown of what I mean by “Bigger is better”.

Bigger Tanks are Easier For Beginners

I know it sounds counter-intuitive, but it’s true, and here’s why.

One of the main aspects of fishkeeping and one of the main “skills” that an aquarist must develop is the ability to maintain healthy water conditions. After all, it’s only the water that matters. It’s where the fish live!

Understanding how to maintain perfect water parameters such as temperature, pH levels, and Ammonia levels are crucial skills that you need to grasp before you start your first tank, but knowing is not enough. You still need to develop a maintenance routine and put in the effort to keep the water as healthy as it can be.

The smaller the tank, the less water it can hold. The less water a tank can hold, the easier it is for any of the parameters to swing out of whack. The more water you have to play with, the more stable the water parameters are, the less you have to change the water and the happier your fish will be.

What size tank should I get?

Water changes are part of the game and they can’t be avoided. However, they can be incredibly stressful to fish if they are done too frequently or aggressively. The smaller the tank, the faster the water will “spoil” and the more frequently you will have to do water changes.

Stressful fish are sick fish and sick fish don’t live as long as they are supposed to. It’s your job as an aquarist to give your aquatic pets the longest and best quality of life possible. That means minimizing stress in as many ways as possible.

It’s not just the quality of the water that can cause stress in your fish either. Imagine being locked in a 10 by 10-meter room with 10 other people for the rest of your life. Now imagine being in a 100 x 100-meter room with those same 10 people. Which one would you prefer?

It’s the same premise as your fish. The more space they have to swim, the happier and less stressed they will be. Stressed fish are more likely to fall victim to a dangerous disease, as their immune systems are considerably weaker.

Think About The Fish You Want To Keep

best fish tank for beginner

When considering the size of your first aquarium, it’s always a good idea to take note of the fish that you are interested in keeping.

Purchasing a 10-gallon tank and then deciding you want to keep Oscar fish is probably not the smartest of ideas. However, if you decide prior to purchasing your tank that you want to keep Oscar fish, a little bit of research will tell you that you need at least 100-gallons to give them the life that they deserve.

Smaller fish such as tetras, guppies, and Rasboras are “beginner” friendly fish that take up less space than other larger fish, so if you are interested in keeping those types of fish, it’s a good idea to then determine how many you want to keep in your tank.

An overpopulated fish tank causes stress in the fish and will throw the water parameters out of whack a lot quicker than having fewer fish, simply because there is less waste to filter out of the water.

It’s always better to understock than to overstock. You can always add more in the future.

What’s The Problem With Smaller Tanks?

If you have made it this far into the article you probably already pieced together the disadvantages of starting with a smaller tank, but here are a few more to consider.

More Unstable Water

I’m not saying it’s impossible to keep fish in a smaller tank because it’s not at all. It’s not much more difficult than a larger tank if you have some experience under your belt. As a beginner though, you need to consider the fact that you will make mistakes, so it’s better to give yourself the additional ”room for error” that you get with larger tanks.

Less Space For The Fish

This one is a no-brainer. The smaller the tank, the less space that your fish have to explore. Fish are aquatic creatures, they need space to swim. There’s nothing worse than seeing a tiny tank that is under filtered and overpopulated. It’s not fair on the fish.

They Require More Maintenance

Again, it sounds counterintuitive, but it’s true. Smaller tanks require more frequent water changes and more frequent cleaning, especially if the water parameters are out of balance. Do yourself a favor and save yourself the hassle. Get a bigger tank and let your underwater universe work in your favor.

Small Tanks Can Stunt Fish Growth

There’s a myth circulating around the world that fish in aquariums will grow according to the size of the tank they are in. While the size that a fish grows to will depend on the size of your tank, it has nothing to do with them “growing to fit the tank” and more to do with the fact that smaller aquariums will stunt the growth of your fish.

When fish’s growth is stunted, they become stressful and more vulnerable to disease. They also live considerably shorter lives than they could if they reached full maturity. You can check out our fish care profiles to understand exactly how large each species of fish is expected to grow.

So What Size Tank Do You Recommend For Beginners?

It’s pretty difficult for me to answer this question with a blanket answer because there are so many variables involved. With that being said, just keep in mind that “bigger is better” and you will be more likely to make the right choice.

10-gallons is a good starting point, but 20-gallons (and beyond) would be the ideal tank for a beginner, budget permitting.

Example of a 55-Gallon Tank

It’s important to consider your budget. A larger tank will obviously be more expensive and it will require more upfront investment to get started (filters, conditioners, heaters etc) but it will save you time and money in the future.

Whatever you think you can afford to spend on a fish tank, bump it up a little bit and go for something bigger, even if it means saving up a little longer. It will be worth it.

Of course, you can still choose a smaller tank as a beginner (10-gallon for example), but you must know that you are limited to just a few small fish. If you want to purchase a smaller tank, make sure you keep the number of fish to a minimum.


Hopefully, my experience with keeping fish in home aquariums and my knowledge of the hobby has helped you understand this topic a little bit more. If not, feel free to leave a comment in the comment section below and I will be happy to answer.

Keeping fish in your home is an amazing hobby and one that you will fall in love with. Do yourself a favor and get started on the right foot. Choosing a larger tank will speed up the learning curve, will give you more room for error and will give you the space to decorate and style your aquarium however you want.

Already got an aquarium? What size did you start with? I’d love to know!

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  1. Hello, I’m an aspiring aquarist and I started with a 10 gallon tank with a few fish. I’m from the Philippines and I got a gold fish and 2 neon tetras. We bought 4 neon tetras but the two of them died. :( I’m still figuring out how to clean the tank and to change the water without stressing the fishes. I got a filter, should I need oxygen on my tank as well?

    1. Itbeganwithabetta says:

      Goldfish are not tropical fish, where as tetras are tropical fish so first off different temperature requirements. Next thing : goldfish produce too much waste for a 10 gallon. They also grow to be very large and need a larger tank (beginning with a 30 but thats only for small goldfish who will grow out of it and then need a larger one) was the tank cycled? New tanks need to be running without fish for atleast a few weeks with water changes and water testing to ensure there is no ammonia or nitrites (there are ways to speed up the cycling process, google them)
      All in all, there were many mistakes made from the start. Id do alot more research if I were you to guarantee a good life for your fish, aswell as a fun hobby to enjoy.

  2. Hey what’s up! Well here are a few things. First off the Goldfish should be kept either alone or with one other Goldfish TOPS in your 10 gallon TANK. Of course a larger tank would be exceptionally Better for your Goldfish. Reason being is because Goldfish naturally give off alot of Ammonia naturally when they eat because they have no stomachs to digest the food. Basically goes right through them… With a bigger tank you have alot more room for them and they can live longer. Rule of thumb for Goldfish is a 20 Gallon tank per Goldfish depending on size as well. If they’re small you could add to but THAT’S ALL! As per your neon tetras you should definitely place them alone with other tetras or with other compatible community fish.

  3. Jamie Stuart says:

    Hi I’ve recently gone out and bought a 54l tank not sure what that is in gallons, I wouldn’t class it as a small tank as I’ve seen lots of 25l/30l/40 etc. So yeah it’s bigger than those tanks, it is a rectangular shape tank don’t know if that makes a difference?

    I was thinking of getting maybe about 4 Platys/Mollies and maybe a couple of bottom feeders and then maybe leaving it at that? Would this be suitable?

  4. 54 l is 14 gallon. (i would really apperciate, if the aquatic comunity would always share the different measerments in metric and nonmetric as well. I mean it’s quite ridicolus watching youtube videos and reading blogposts having a gallon to liter, an inch to cm and a fahrenheit to celsius converter also open :D #mylife)

    I’m (also aspiring future tank-owner) planning to build a 112 l (30 gallons) tank and I would really apperciate your opinion. I plan to populate the tank as follows: 1 Betta, 6 Glass bloodfin tetra, 2 Amano shrimp, 8 neon tetra, 6 gold barb, 4 kuhli loach and maybe 3 african dwarf frog. What do you think? I mean, with a good filter and planted tank.
    To be honest I would prefer instead of the kuhli loach to have hillystream loach and instead of the gold barb to have wither platy or guppy, but as I see the hillstream loach prefer harder water and stronger waterflow than the rest of the tank, also the guppy has a problem with the hardness of the water (and I’m quite unsure about them as I read that I might end up with way more guppy than I signed up for quite easy, mixing that I might and up with 3 really hefty frog and a lot of unwanted guppy). Water hardness seems also be the problem with the platy as well.
    Guys, what do you think? Thanks!

  5. Alison Thompson says:

    I would suggest pygmy loach 5 if possible.Very active and such fun to watch they help clear detritus in the tank.
    Cardinal tetra are attractive and swim in small groups as do Harlequin rasbora pretty friendly little fish. I read somewhere odd numbers of fish 3 or 5
    rather than an even number are happiest ? ?
    Fish also benefit from a well planted tank with places to rest. I have 5 tiger barbs who are non-aggressive though they do have a reputation for nipping.They are all male so this could be the reason. I have a bristlenose plec who needs drift wood as do the shrimps. Recently I bought crystal shrimp and they have produced young. All are doing well and have their own spaces. The plec has a ‘flint cave’ found on my ipad and not too pricey. Meadow cloud minnows are also an attractive shoal of fish

  6. I started with a 2 gallon and 6 WCM minnows and two amino shrimp which I had a month before buying a 16 gallon and added 4 more amanos and 14 more WCM minnows and 4 Hillsteam loaches.(I added a wave maker which was/is greatly appreciated by the WCM minnows.) the back is heavily planeted and the foreground decorated with large pebbles to create a river like scenario- so the WCM minnows have plenty of space to swim and to hide.Now I ordered a 40 Gallon to give them more space and to add a small group of 10 Checkered barbs.The 2 gallon one is redecorated and cycled and home to a daphnia colony.I have also a 7.9.gallon high cube which was originally for the caridinia shrimp before I used it for a small group of 6 juvenile checker bars.
    They got eaten.Not sure if I will use it for a Betta and a few aminos and a couple of compatible loaches or get caridina’s again and a few chilli rasbora.
    Personally I’m glad I started small as I’m slowly upsizing.and even thinking of moving place to get a larger tank.If I would have started big I would already have space problems, lol.

    1. When keeping fish of any kind, starting small is always a good idea. Good job!

  7. I really appreciated your article. I love the calming effect and watching the fish “do it’s thing”. I learned quite a bit from your article and I know it will help me in the future. I purchased a large fish bowl fitting about1 1/2 gallons of water. I noticed my male Betta fish is making a bubble nest. That is why I read you article and learned so much. I was afraid he was not getting enough Oxygen. The pet shop informed me to change 1/2 of the water weekly and feed him three times a day. I have been feeding him twice a day, what do you think? Should I purchase a female for him? I plan to get a bigger tank in the future when I have saved for the investment. I do not was my betta to be coupled up and I find the people in the pet store give very basic info if you can get it at all. I will definitely be referring to you information on a regular basis. Thank you so much! From a beginner.
    Debby, New Brunswick, Canada

  8. Jeff Schmitt says:

    I first got into fishes about 1980 through a friend who helped me set up my first tank. It was a 135 gal. I had Bala Sharks, Tinfoil Barbs, Jack Dempseys, Convicts, and an Arowana, which grew to 18″ before he broke the heater one night. I didn’t find out until he was listing, and by then it was too late.

    I had another similar sized tank for a while, but it eventually started leaking, so I gave away my fish and the tank which was turned into a terrarium. Big tanks and big fish are a lot of work, and my business was taking a lot of time, so I gave up the fish tank scene for a while.

    My wife surprised me with a 72 gal bow front tank with all the fixins about 20 years ago, and I got back into the fish scene with many of the same type of fish as before. I kept that tank running for about 10 years, but the back filter began leaking without my knowledge, and some of the more aggressive fish started bullying the more passive fish, and I started having water quality issues. I had bought a new back filter, but couldn’t get it to run. I eventually lost all of my fish. I cleaned out the tank, and it sat dormant in my living room for the last 10 years, begging me to get back into it.

    I spent last weekend cleaning the tank, the rocks, the gravel, & the filters. I filled it up with water, about 1/4 of the way to start to make sure there were no leaks. I worked on the back filter, and got it to run, but with a terribly loud grinding noise. After messing with it a bit, and letting it run by itself, it quieted down, and seems to be running okay. It has been cycling for 3 days, and after adding nitrifying bacteria to speed up the process 2 days ago, it is still not quite ready. The fish gurus at my local fish shop recommended doing a 1/2 tank water change, and adding another bottle of nitrifying bacteria, and letting it cycle for another few days.

    This waiting is killing me, but I do want a healthy tank. In the mean time, I ordered a new heater (I don’t really trust a 20 year old heater), and a new thermometer. Things have changed a lot in the last 20 years.

    I do have a question. My 20 year old bow front tank has a few issues, mostly to do with the plastic deteriorating. The plastic top has broken, and doesn’t fully support the glass lids. I jury-rigged a flat piece of metal to span across the top of the tank, but it isn’t very pretty. Also, the plastic at the back of the glass lids is brittle, and has cracked. Are there any replacement parts for older fish tanks?

    I enjoyed reading your article, and I do agree that larger tanks are much more stable, although I have never really owned a small tank. I think I will be cruising this site quite a bit in the future. Thank you

    1. You’ve had quite the experience with fish keeping, Jerry! I’d recommend, if possible, replacing the old tank entirely instead of its parts. I fear that other bits may also wear away with time, and lead you right back to square one! Hope this helps!

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