Choosing an aquarium tank for your pet fish can be a difficult task. Not only does it need to meet their needs (type, size, placement), but it must meet yours as well; a tank that doesn’t fit your home will hinder your ability to care for and appreciate your fishy friends. Follow our top tips about how to select an aquarium tank and set it up correctly.

Choosing a fish species

There are quite a few factors to consider when choosing the fish for your aquarium:

• How big will the species get? The potential growth of the fish will dictate what size fish tank you should home them in.
• What are the required aquarium water parameters for the fish? You’ll need to explore details such as temperature and pH ranges.
• Is the species known to breed easily in captivity? If so, do you have the equipment needed to keep the babies or an appropriate plan to rehome them? It’s worth finding out if your local fish shop/pet shop will take the young fish. If you do not have the means to keep or rehome them, you should choose fish that don’t breed as easily in captivity.
• Is the species of fish easily susceptible to certain fish diseases? Get clued up on how to prevent and treat different types of diseases.

If you already have fish or are planning to buy a few different species, it’s important to consider how they’ll get along together. What is the temperment of each fish species? Do they all eat the same/similar type of fish food? Is your tank big enough for them all?

Factors to consider when choosing a tank

• Size: One of the primary considerations in choosing an aquarium tank is determining the size that it needs to be. Generally speaking, large fish tanks tend to be more expensive so, before you set your heart on a giant of a tank, you should determine how much you want to spend.
• Placement: You will need to consider where you will keep the aquarium; this will help you determine how big an aquarium you can have. It should be placed where it will be seen but not in the busiest part of the house, as excessive activity can disturb your fishy friends. You will need to keep the tank out of direct sunlight, as this can contribute to algae growth and cause temperature fluctuations. Equally, the tank should be kept away from windows or vents, as air drafts can disrupt the environment of the aquarium.
• Size and species: Naturally, the larger the fish, the larger the tank they will need. It’s a good idea to determine the maximum size of the tank you can fit your home before researching what fish and how many will fit in it.
• Tank material: Acrylic tanks come in more shapes, are clearer, and are more heat-resistant. Glass tanks, however, are much cheaper and more resistant to scratching/damage.

Freshwater tropical aquariums

Tropical fish tanks should generally be kept around 25°C. However, there are some tropical fish, such as guppies, that can survive in far lower temperatures. Chat with your local fish shop about the types of fish you want to keep and their best temperature range. You will need a heater to ensure the tank is kept at the appropriate temperature – a popular choice is a combination heater-thermostat in one unit (known as a heater-stat), which will monitor the temperature and maintain it at the temperature you set. The thermostat can be set to a specific temperature and the heater will turn on if the water temperature dips below this setting.

Coldwater aquariums

A coldwater fish tank is exactly what it sounds like: a colder, freshwater aquarium. The temperature is usually below 21°C or at least room temperature in most homes. One of the most common coldwater species kept in a coldwater aquarium is the goldfish. Whilst you may remember having a goldfish bowl as a child, many people today have goldfish tanks. Setting up an aquarium rather than a fish bowl can dramatically lengthen the lifespan of your goldfish, and is as simple as adding the proper equipment. Coldwater freshwater fish may be a little more expensive when you start shopping for species other than the standard goldfish. Koi and goldfish ponds are great examples of domesticated coldwater fish habitats.

Marine aquariums

Marine tanks require saltwater for the fish to survive. Salt must be purchased and mixed before adding water to the tank from an approved pet store or supplier – just using sea water will not be suitable. Marine tanks offer beautiful saltwater fish, colourful corals, and spectacular invertebrates to admire. These specimens are usually significantly higher in price in comparison to their tropical freshwater friends. In general, marine fish are a little more sensitive to water parameters (conditions), some require specialised diets, and it can be difficult to find a supplier or fish store. Marine aquarium equipment is significantly more expensive due to keeping coral.

Fish-only (FO) aquariums

Fish-only tanks do not feature aquatic plants. Although this design is the least expensive set-up, it is not necessarily the easiest. Getting started will require time to establish a proper nitrogen cycle within the tank due to the absence of plant matter. Maintenance frequency will also be increased when compared to tanks with living rocks and coral. You will need to stay on top of water conditions and diligently monitor pH, nitrogen, and ammonia levels.

Fish-only with live Rock (FOWLR) aquariums

The set-up is the same as a fish-only tank with the addition of live rock and better lighting. Rocks with creatures living inside them and on the surface, thus the name, have really taken off the last few years as an excellent source of natural biological filtration. It’s worth noting that getting healthy rocks is important. A good rule of thumb to use is 1.5 pounds of rock to a gallon of water. You will still need to monitor water quality, however, you should find that changes will be more gradual and the tank should require fewer large adjustments.

Reef aquariums

Taking the live rock concept one step farther, advanced fish owners can set up a tank geared toward corals, anemones, and invertebrates. Fish are usually an afterthought in these types of tanks, as the focus tends to be on keeping the coral and anemones growing. Reef tanks are complicated systems and one is usually only set up once a fish keeper has enough experience and knowledge to manage it (or knows someone that does). The water quality generally has to be tested very frequently in comparison to freshwater tanks.

Introducing fish to the tank

Once you have your tank set up, you will need to fill it with the water you intend to use, add water conditioner, and then leave for roughly a week before adding any fish or live media – this will allow the tank’s natural bacterial environment to form. Some people suggest adding a small amount of food (flakes) to kick start the nitrogen cycle, as it breaks down naturally in the water, releasing waste products and ammonia. A small number of ‘hardy fish’ can also be added to help establish a nitrogen cycle, but be aware that this can be risky depending on how much the parameters fluctuate. Adding fish to a newly established tank will always see an ammonia spike, so be sure to feed sparingly until the tanks natural bacteria has built up enough to break it down. Once you have tested the water to ensure its PH and nitrates/nitrites are within recommended ranges, you can look to add other types of fish. If you have a marine tank, you will need to add live media after a week and then wait another week before adding any fish.

Our articles are not a replacement for face-to-face vet advice. It’s important to consult with your vet on a regular basis to raise any pet concerns that you may have.

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