Evaluating Aquariums – Size Matters
No matter if you are new to fishkeeping or not, being able to interact with live aquatic animals can be exciting! There is no doubt that if you are new to fishkeeping one of the first questions you may have is “What type of aquarium size is best to get as a beginner?” The answer must depend on many things, especially on what type of fish you want to keep, how much space you have, and your abilities to take care of the tank you choose. This article will look at the best aquarium sizes for beginners and keep in mind to consider all of the factors that must be taken into consideration.
Understanding Aquarium Size
The size of your aquarium is critical to the health and well-being of your fish. In general, the larger the aquarium is, the easier it is to manage, and the more stable the aquatic environment will be. Smaller tanks are very finicky, and small changes to the water conditions can stress fish. Let’s take a closer look at aquarium size, noting benefits and drawbacks to small tank size as well.
Small Aquariums (2.5 to 10 Gallons)
Small aquariums, or nano tanks, seem attractive to new fishkeepers, not only because there are so many cool fish hanging out in the Lakes and Oceans that we have available to keep, but also because there is considerable savings in the low price and low amounts of space taken.
However, they come with their own obstacles.
- Pros:
- Less expensive to buy and less expensive to upkeep.
- It is perfect for small areas such as apartments or dorms.
- Perfect for small fish or shrimp species.
- Cons:
- Water quality can change drastically and often, which takes extra attention.
- Choice of fish and plant life is limited.
- Less forgiving of beginner mistakes.
Popular small species of fish for these tanks are Betta fish, guppies, and neon tetras. If you decide on a small aquarium set-up, keep in mind this style will require more water changes and maintenance.
Medium Aquariums (10 to 30 Gallons)
Medium aquariums help in achieving two main things which are less effort and still addresses your need to keep multiple species of fish. Most of the beginners who I have talked with and other experiences I have seen, a tank in the medium range left a better experience than low maintenance tanks.
- Pros:
- Stable water conditions compared to smaller tanks.
- Larger selection of fish and plants to choose from.
- Most aquarium size allows for a small community set up.
- Cons:
- A good size higher price tag to set up and maintain.
- It will require more space than a small aquarium, but less than the size of tank you need for the community set up.
- Ongoing care will still take focused attention.
I have seen many beginner aquarists be advised to start with a 20-gallon tank. This tank will allow you to keep a community of fish. Small community of tetras, few corydoras, one or two larger species if you like like an angelfish.
Large Aquariums (30+ Gallons)
Large Aquariums are an excellent choice for the aquarist who is willing to commit to time and money for their hobby. Aquariums are, by far, the most stable water quality and provide a wide range of options for life!
- Pros:
- Stable water parameters makes for easier maintenance.
- Housing larger fish (and a wider range of species).
- Creating more sophisticated aquascapes and ecosystems.
- Cons:
- Requires a larger investment to get started (tank, equipment and maintenance).
- Requires a larger physical footprint – may take a fair amount of work to set up.
- Requires moderately complex – filtration, heating (depending on species).
If you are planning on keeping a larger aquarium, consider a number of species including cichlids or a larger community of fish and have appropriate space and resources for the maintenance requirements of all specific species on board.
Factors to consider when planning the size of your aquarium!
When considering all points in choosing the best size aquarium for you, keep some factors in mind.
- Space – take a look at where you want the aquarium and importance of having it fit in its space, room for maintenance if needed (behind the tank), equipment (if stand alone), etc.
- Budget – take into consideration your aquarium cost, filtration system, tank heater, substrate, ornaments, fish, and the associated start up to get going. Bigger generally costs more (tank set up costs extra costs).
- Fish Species – Do some research on what types of fish and all space requirements. While some fish may flourish in larger more open spaces, others are well suited to small spaces.
- Maintenance – How much time do you commit to your aquarium water quality dependance, larger tanks require more equipment, but maybe less frequent water changing than smaller.
Setting up your first aquarium;
Once you choose and size your aquarium … you’re ready to start! Here’s a quick outline …
- Choose a site – select a flat, stable surface, away from direct sunlight and sources of heat.
- Get your kit together – tank, filter, heater, substrate, ornaments or gravel for the base material, water conditioner (temporary dechlorinater) or however you are providing your water content safe, preparation.
- Set it all up – rinse the tank and equipment (do not use soap!), add substrate and set up your ornaments, and fill the tank with conditioned water!
- Cycle your tank – leave it to cycle for a minimum of 4-6 weeks to establish healthy bio levels – before adding fish.
- Add fish slowly – ensure you maintain water quality checks as you introduce a fish to keep the tank balanced.
Conclusion
Selecting the best aquarium size, particularly for beginners will depend ultimately on your conditions; space, budget and level of care of the fish species you are wanting to keep. While the small tanks are strong collectorspeg tanks, generally the middle size aquariums tend to provide the best balanced out for initial fishkeepers. Regardless of the aquarium size, remember again patience, and consistent maintenance will be foundational to a successful aquatic environment. Goodluck with your journey!

