What size aquarium should a beginner buy?

A 20- to 40-gallon rectangular glass tank is ideal. It's large enough to maintain stable water parameters but manageable for a first-time owner.

Is glass or acrylic better for freshwater tanks?

Glass is more scratch-resistant and affordable, making it the go-to for most freshwater setups. Acrylic is lighter but scratches easily.

Do I need a filter if I have live plants?

Yes, even planted tanks need a filter to circulate water and provide biological filtration. Plants alone can't handle fish waste.

How often should I clean my aquarium?

Perform partial water changes of 20-30% every two weeks, and clean the filter media monthly. Avoid overcleaning to preserve beneficial bacteria.

Why is a bigger tank easier for beginners?

More water dilutes waste and resists rapid temperature and chemistry swings, giving you more margin for error. Tiny tanks and bowls go wrong far faster.

What does cycling a tank mean?

It is growing the beneficial bacteria that convert fish waste into less harmful compounds. Cycle over several weeks before adding fish, and stock slowly afterwards.

Aquariums & Tanks: A Complete Buyer’s Guide

Introduction

Setting up a new aquarium is an exciting step into the world of fishkeeping. Whether you’re a first-time owner or upgrading your setup, choosing the right tank is crucial for your fish’s health and your enjoyment. With so many options, glass versus acrylic, all-in-one kits versus custom builds, it’s easy to feel overwhelmed. This owner-to-owner guide will walk you through what matters most, from materials and size to filtration and lighting, so you can pick a tank that fits your space, budget, and fish species.

What to Look For

When shopping for an aquarium, focus on these key features:

Tank Material: Glass is scratch-resistant and typically cheaper, but heavier. Acrylic is lighter and clearer, but scratches easily. For large tanks, acrylic may be easier to move.

Size and Shape: A larger tank is more stable and forgiving for beginners. Rectangular tanks offer more swimming space and better gas exchange than tall or bow-front designs. Standard sizes like 20, 29, 55, and 75 gallons are common.

Filtration System: The filter should turn over the tank volume 4-6 times per hour. Look for a filter with mechanical, biological, and chemical media. Many all-in-one tanks include a built-in filter, but you can also buy separate canister or hang-on-back filters.

Lighting: If you plan to keep live plants, choose a full-spectrum LED light with adjustable intensity and a timer. For fish-only tanks, basic lighting is sufficient.

Hood or Lid: A tight-fitting lid prevents fish from jumping out and reduces evaporation. Glass lids are popular, but plastic frames can warp over time.

Stand Compatibility: Ensure the tank sits on a level, sturdy stand. A 55-gallon tank weighs over 600 pounds when full, so a proper stand is non-negotiable.

Top Types to Consider

Glass All-in-One (AIO) Kits

These are pre-assembled tanks with built-in filtration and lighting. Brands like Fluval and Red Sea offer AIOs that are beginner-friendly and clean-looking. Pros: No external equipment needed; easy setup; modern design. Great for small reef systems or planted tanks.

Acrylic Aquariums

Acrylic tanks are lighter and stronger than glass. They come in unique shapes and sizes. Pros: Seamless viewing; better insulation; less prone to breakage. However, they scratch easily, use a soft cloth for cleaning.

Rimless Tanks

These have no plastic frame, offering a sleek, modern look. Pros: Unobstructed view; ideal for aquascaping. They often require a sturdy stand and careful handling to avoid stress on seams.

Column or Bow-Front Tanks

Tall or curved tanks are striking but less practical. Pros: Unique aesthetic. Cons: Less surface area for gas exchange; harder to light and clean. Best for expert owners who want a centerpiece display.

How to Choose

Start with the fish you want to keep. Community fish like tetras and guppies do well in 20-gallon longs, while goldfish need at least 30 gallons. Reef tanks require stable parameters and good lighting. Also consider your space: measure the area and account for a stand and equipment. If you’re a beginner, a 20- to 40-gallon glass rectangle is your safest bet, it’s forgiving and easy to maintain.

Check the warranty: most glass tanks have 1-5 years. For acrylic, some offer lifetime warranties against leaks. Think about future upgrades, buying a larger tank now can save you money later.

When you’re ready, check the current price on Amazon for the type you’re considering to see what fits your budget.

Common Mistakes to Avoid

Buying too small: A tiny tank is harder to keep stable. Go as large as your space and budget allow.
Ignoring the stand: A wobbly or undersized stand can cause the tank to crack.
Overstocking too quickly: Let your cycle complete before adding fish.
Using tap water without conditioner: Chlorine and chloramine are deadly. Always use a dechlorinator.
Choosing a tall tank for deep-bodied fish: Fish like angelfish need horizontal space, not height.
Skipping a quarantine tank: New fish can introduce diseases. A separate tank is essential for long-term health.

Bottom Line

The best aquarium is the one that fits your lifestyle, space, and the fish you want to keep. Start with a sturdy glass rectangle, invest in a quality filter and heater, and prioritize stability over flashy features. Take your time, research your species, and don’t cut corners on the stand or lighting if you plan to keep plants. With the right setup, your aquarium will be a thriving ecosystem and a source of joy for years to come.

Check current prices on Amazon

Sources

AKC
ASPCA

What you need to know

When buying an aquarium, bigger is usually easier to keep stable, as a larger water volume dilutes waste and buffers temperature swings that stress fish. Avoid tiny bowls, which lack space for filtration and quickly turn toxic. Match the tank to the adult size and number of your intended fish, and factor in a filter, heater for tropical species, and a secure lid to prevent jumpers escaping.

Plan to cycle a new tank before adding fish, growing the beneficial bacteria that process ammonia over several weeks. Test the water during this period and stock slowly to avoid overwhelming the system. Choose a sturdy, level stand, as a filled tank is very heavy. Research the specific water parameters and compatibility of any fish before buying, since mismatched species and overstocking are the most common causes of early losses.