While a fish tank might not be technologically complex, there are several factors to weigh when choosing the right one for you and your fish.

One of the most important decisions about choosing a new tank is its size. Fish tanks are measured by gallons of water held, not by physical measurements, although obviously the more gallons a tank can hold, the larger it has to be. You’ll find tanks as small as one gallon and as large as 100 gallons or more, along with many sizes in between.

As a general rule, when it comes to fish tanks, the larger the better. A larger tank has room for more fish, but more importantly, the water is less likely to become overloaded with toxins from fish waste in a bigger tank. For beginners, it’s best to go no smaller than a 10-gallon tank, although most experienced fish owners recommend a 20-gallon or 29-gallon tank if space allows.

You have two choices of material for your fish tank: glass and acrylic.

Glass fish tanks are the traditional choice and are almost always rectangular. Glass tanks are usually less expensive than acrylic and don’t easily scratch, making them a good choice for beginners. On the downside, glass is heavy and can shatter if dropped or struck. A glass tank can be set on a stand with support only around the bottom edges, although it’s best if your tank is fully supported.

Acrylic fish tanks come in a wide range of shapes, including square, round, and semicircular. You’ll pay more for an acrylic tank and most likely will eventually scratch the tank, as acrylic is very prone to damage. Acrylic tanks weigh much less than glass tanks, which is an important consideration if you’re planning on buying a large tank. Acrylic tanks must be fully supported underneath to prevent bowing or breaking.

The traditional fish tank is rectangular. This is also the best choice for your fish’s health because a rectangular tank exposes a larger surface area of water to the air, which results in better oxygenation. But if space or personal preference mitigates against the use of a rectangular tank, you’ll also find tanks that are taller than they are wide, as well as cubical tanks, domed-front tanks, and even round tanks.

Your fish tank needs a lid to reduce water evaporation, to prevent your fish from jumping out, and to keep curious pets and children from fishing in the tank. The most basic lids are hinged glass and require the use of a separate light fixture. Beginners often prefer hoods, which are lids that incorporate a light fixture to illuminate the tank. Typically, a lighted hood is included with a fish tank kit.

The following accessories are must-haves for a freshwater aquarium. Always take care to choose accessories that match the size of your fish tank.

Filtration system: AquaClear Power Filter
Every tank requires a filtration system to remove toxins, excess food, fish waste, and other contaminants from the water. There are many styles of aquarium filtration systems, but most beginners find that a power filter that hangs on the back of the tank is best. The AquaClear Power Filter is a solid choice that’s energy-efficient and easy to install.

Heater: Fluval M Submersible Heater
While goldfish are generally okay without an aquarium heater, most tropical fish require water temperatures of 74°F to 78°F, meaning you’ll need a submersible heater to keep the water comfortable for your finned pets’ health. We like the Fluval M Submersible Heater to keep water temperature steady.

Thermometer: Fusion Smart Temp Aquarium Thermometer
A simple submersible thermometer that attaches to the side of the tank with a magnet or suction cup makes it a cinch to monitor water temperature. The Fusion Smart Temp Aquarium Thermometer is a decent magnetic model that’s inexpensive and easy to read.

Substrate: GloFish Aquarium Gravel
Gravel is the most common fish tank substrate, as it’s inexpensive, comes in lots of colors, and works very well to support colonies of beneficial bacteria that keep the water balanced and the fish healthy. We like GloFish Aquarium gravel, which is available in a wide range of colors.

Price is largely based on size, material, and included supplies. Because of that, it’s difficult to generalize about aquarium prices, but the following guidelines will give you an idea of how much you’ll be spending.

Inexpensive: Below $50, you’ll get a very small tank with a few pieces of basic equipment, such as the light and heater. Expect to add a power filter separately. 

Mid-range: Between $50 and $125, expect better-quality equipment and a larger tank. Still, you may have to purchase some necessary supplies, such as the filter, separately.

Expensive: Above $125 is where you’ll find larger tanks and more complete setups that include high-quality accessories. For a fully stocked, all-included aquarium of 20 or more gallons, you should expect to pay over $200.

Regular care will keep your fish happy and healthy.

• Condition the water. Treat water with a dechlorinating water conditioner before adding it to your tank.
• Test regularly. Use an aquarium water testing kit weekly to make sure your tank isn’t building up harmful levels of ammonia, nitrite, or nitrate. If necessary, change up to 25% of the water to restore balance.
• Clean your gravel. Vacuum the gravel every other week with a gravel vacuum cleaner to remove fish waste, uneaten food, and algae.
• Battle the algae. Use a tank scraper or cleaner to remove algae from the sides of your tank every other week.
• Monitor the water temperature. Check your tank thermometer each day, and adjust the heater if necessary.
• Do a daily welfare check. Count your fish daily, and watch them for at least a few minutes to be sure they look healthy. Signs of illness include abnormal spots or streaks on the fish’s body or fins, floating near the surface, irregular swimming patterns, fins tightly clamped against the body, or lying on the tank bottom.
• Maintain your filter system. Change or clean the filter in your power filtration system on the schedule recommended by the manufacturer.

While we stand by our highlighted favorites, there are plenty of other great fish tanks on the market. If you’re looking for a home for a Betta fish or just a couple of small freshwater fish, you’ll like the compact size and completeness of the Hygger Horizon 8-Gallon Aquarium Kit. The glass tank has a uniquely curved front panel and a craggy “cliff” that fits against the back panel. The kit includes a filter and light, as well.

But if you prefer to go big, check out the 55-gallon aquarium kit from Tetra. Along with the sturdy glass tank that’s large enough to house quite a few fish, you’ll get just about everything else needed to start up your fish tank, including a heater, filter, thermometer, water conditioner, net, hinged hood with light, faux plants, and a brochure on fish care.

Q. What’s the best location for my fish tank?
A. Ideally, your aquarium should be located where you and the family can most enjoy it, but there are a few other considerations, as well. You’ll want the tank near an electrical outlet, as you’ll need to plug in the filter, light, and heater. Fish need a regular cycle of light and darkness, so your tank should be reasonably close to a window, but not so close that direct sunlight shines onto the tank. Direct sunlight promotes the growth of algae and can overheat the water, both of which may harm the health of your fish.

Other areas to avoid placing a tank include: close to air-conditioning or heating vents, near doorways or other high-traffic areas, or directly on the floor. All of these locations can be stressful for your fish.
 

Q. What about a saltwater tank?
A. While many saltwater fish are colorful and unique, it’s often best to leave these delicate and expensive beauties to experienced aquarium enthusiasts. Setting up and maintaining a saltwater tank is considerably more complex than a freshwater tank, and requires a large tank for the best results.
 

Q. What other items do I need to set up my fish tank?
A. Along with the necessary accessories outlined above, there are several other items that make caring for your fish easier and more enjoyable.

• Decorations inside the tank, including faux or real plants, rocks, fanciful decorations such as sunken ships or treasure chests, and whatever else strikes your fancy give the tank character, but more importantly, give your fish somewhere to hide when they feel stressed or insecure.
• You’ll need fish food formulated specifically for your type of fish.
• A net makes it easy to catch your pets when it’s necessary to move them from the tank.
• Every aquarium owner should have a water testing kit that tests pH and levels of ammonia, nitrite, and nitrate.
• A siphon with a hose and a clean bucket — not a bucket that’s been used for household cleaning supplies — are musts for making water changes.