Pet Supplies Plus sells 20-gallon aquarium tanks, typically as bare tanks or starter kits, at prices that are competitive with other pet retail chains. You'll usually find the Aqueon 20 Gallon High or 20 Gallon Long at Pet Supplies Plus locations, along with basic starter kits that include a filter, heater, and lid. Prices vary by store and promotion, but bare 20-gallon tanks generally run $25-50, while complete starter kits land in the $60-100 range depending on what's included.

This guide covers everything you need to know about buying and setting up a 20-gallon aquarium from Pet Supplies Plus, including which kit components are worth keeping, what you'll want to upgrade or add, and how to cycle the tank correctly before adding fish.

What Pet Supplies Plus 20 Gallon Tanks Include

Most 20-gallon setups sold at Pet Supplies Plus are Aqueon brand products. Aqueon is Spectrum Brands' aquarium line, widely distributed through pet retail chains, and their 20-gallon tanks are made from standard float glass with silicone seals rated for long-term use.

Bare Tank vs. Starter Kit

If you buy just the glass tank, you get the tank, a plastic frame trim at top and bottom, and nothing else. This is the budget option and makes sense if you already own equipment or plan to buy specific components separately.

The Aqueon Aquarium Starter Kit 20 is the most common bundled option. It typically includes:

  • 20-gallon glass tank (choice of High or Long configuration)
  • QuietFlow LED PRO 20 power filter (rated for 20-gallon tanks)
  • Submersible preset heater (usually 100 watts)
  • Thermometer strip
  • Fish net
  • Water conditioner sample
  • Fish food sample
  • LED hood with light

This is a functional beginner kit. It has everything you need to get water in the tank and fish fed. The quality of individual components varies, which I'll address below.

20 Gallon High vs. 20 Gallon Long

The 20 Gallon High measures approximately 24x12x16 inches. The 20 Gallon Long (also called a 20L) measures approximately 30x12x12 inches. They hold the same volume but have very different shapes.

For fish keeping, the 20 Long is generally preferred. Fish like tetras, danios, corydoras, and livebearers are horizontal swimmers. The extra footprint of the Long gives them more room to move and allows a longer aquascape. The 20 High is better for taller aquascapes or fish like angelfish that prefer more vertical swimming space.

For planted tanks specifically, the 20 Long's wider footprint is easier to light evenly and allows more planting zone variation.

Equipment Included in the Starter Kit: What to Keep and What to Upgrade

The starter kit gets you running, but some components are worth upgrading once you understand the tank's needs.

The QuietFlow LED PRO 20 Filter

This is a decent beginner hang-on-back filter. It uses a cartridge with activated carbon and mechanical filtration media. The carbon cartridge does remove some toxins and odors initially, but Aqueon recommends replacing the cartridge monthly, which is an ongoing expense and also strips beneficial bacteria when you toss the old cartridge. A better approach is to run the filter with permanent sponge or ceramic media and add a small mesh bag of activated carbon that you replace every 4-6 weeks without disturbing the bacteria colony.

For most community fish tanks, the QuietFlow PRO 20 provides adequate filtration. If you plan to overstock or keep sensitive species, consider upgrading to an Aquaclear 30 or Fluval 207 canister down the line.

The Preset Heater

The preset heater in Aqueon starter kits is usually fixed at 78 degrees Fahrenheit with no adjustment. This works fine for most tropical fish (78 degrees is a solid middle-of-the-road temperature), but you can't adjust it for species that prefer cooler or warmer conditions. If you're keeping fish with specific temperature needs, buy a fully adjustable heater separately. The Cobalt Neo-Therm 75W or the Eheim Jager 50W are reliable upgrades in the $20-30 range.

The LED Hood

The stock LED hood is low-intensity and suitable only for fish tanks or very undemanding live plants like Java fern, Anubias, and Java moss. If you want a planted tank with stem plants or carpeting plants, you'll need a separate light. The Fluval Plant 3.0 for 24-inch fixtures, the Current USA Satellite+ Pro, or the Beamswork DA FSPEC are purpose-built planted tank lights that fit 20-gallon setups.

Setting Up Your 20 Gallon Tank

Once you have the tank home, the setup process is straightforward but the cycle stage takes time that most beginners underestimate.

Step 1: Rinse Everything

Rinse the tank, gravel, decorations, and any equipment with plain water. Don't use soap. Soap residue is toxic to fish and almost impossible to rinse completely from porous surfaces.

Step 2: Add Substrate

For a basic fish-only or low-tech planted tank, standard aquarium gravel or a fluorite-based planted substrate works well. Fill to about 2 inches depth for fish-only, or 2-3 inches for planted setups. If you're building a planted tank, Fluval Stratum, ADA Amazonia, or UNS Controsoil are nutrient-rich substrates that support plant roots without CO2.

Step 3: Add Hardscape and Decorations

Place rocks, wood, and decorations before filling with water. Driftwood like Mopani or spider wood adds tannins to the water (beneficial for many South American fish but turns water tea-colored). Soak driftwood for 1-2 weeks before adding it if you want clear water.

Step 4: Fill and Dechlorinate

Fill with tap water and add a dechlorinator immediately. Seachem Prime is the standard choice. It detoxifies chlorine, chloramine, and heavy metals and also temporarily detoxifies ammonia during cycling, making it safer to add fish before the cycle completes.

Step 5: Cycle the Tank

This is the stage most beginners rush and pay for later. The nitrogen cycle establishes colonies of Nitrosomonas bacteria that convert ammonia to nitrite, and Nitrobacter/Nitrospira bacteria that convert nitrite to nitrate. Without this cycle, ammonia and nitrite accumulate to lethal levels for fish.

Cycling takes 4-6 weeks using fish food or pure ammonia as a nitrogen source, or 1-2 weeks if you use bottled bacteria products like Dr. Tim's One and Only or Seachem Stability combined with established filter media from another cycled tank.

You know the cycle is complete when you can add ammonia to the tank and see it drop to 0 ppm within 24 hours, with nitrite also at 0 ppm. Nitrate will be present (it's the end product) and should be kept below 20 ppm through regular water changes.

Equipment You'll Want to Add

Beyond the starter kit, a few additional items improve the tank significantly:

  • Air pump and sponge filter: Running a small sponge filter like the Hikari Bacto-Surge as secondary filtration adds biological capacity and creates a backup colony of bacteria
  • Gravel vacuum: The Python No Spill or a simple Lee's gravel vacuum makes water changes painless
  • Liquid test kit: The API Freshwater Master Test Kit tests pH, ammonia, nitrite, and nitrate. You need this during cycling and for ongoing maintenance
  • Chiller or additional cooling: If you're in a warm climate, see our best chiller for 20 gallon aquarium guide for compact cooling options

For a broader look at equipment upgrades, our best aquarium equipment roundup covers filters, heaters, lights, and more.

Fish and Stocking for a 20 Gallon

The 20 gallon is one of the most versatile freshwater tank sizes. Here are some realistic stocking options:

  • Community tank: 6-8 small tetras (neon, cardinal, ember), 4-6 corydoras catfish, 1-2 dwarf gourami
  • Single species tank: 6-10 celestial pearl danios or chili rasboras in a planted nano setup
  • Betta tank: One betta with 6 corydoras and some snails or shrimp
  • 20 Long planted: A Dutch-style planted tank with a school of harlequin rasboras or cherry barbs

Avoid goldfish (produce enormous waste for their size), oscars (grow to 12+ inches), or any species labeled for 40+ gallon tanks at the store.

FAQ

Does Pet Supplies Plus have good sales on 20 gallon tanks?

Pet Supplies Plus runs sales on aquarium equipment periodically, often tied to spring and summer when fish-keeping interest spikes. The most common promotions are dollar-per-gallon sales on bare tanks or bundled kit discounts of 20-30% off. Following their weekly ad online or signing up for their Pals Rewards program gives you advance notice of these sales.

Is the Aqueon starter kit filter good enough for a 20 gallon tank?

It's adequate for a lightly stocked community tank with regular maintenance. The QuietFlow PRO 20 provides decent mechanical and biological filtration for the price. Where it falls short is long-term media management (the cartridge system strips bacteria at replacement) and flow rate for heavily stocked tanks. For most beginners with a standard community fish setup, it works fine for the first year before you know what you actually need.

Can I use the Pet Supplies Plus 20 gallon tank for a saltwater setup?

Yes, a standard glass aquarium holds saltwater the same as freshwater. The limitation is that the starter kit equipment (filter, heater, light) is not adequate for a saltwater or reef tank. You'd use just the tank itself and build a saltwater-appropriate equipment list from scratch, including a protein skimmer, reef-capable lighting if you want corals, a quality return pump, and live rock.

How much does it cost to fully set up a 20 gallon tank from Pet Supplies Plus?

If you buy a starter kit ($60-100), you already have the basics. Adding a liquid test kit ($25-30), dechlorinator ($10-15), substrate upgrade ($15-30), and a better light for plants ($40-100 if desired) brings the total to roughly $150-275 for a nicely equipped 20-gallon setup. This assumes the stock filter and heater from the kit are kept, which is reasonable for a beginner community tank.

Getting Started the Right Way

Buy the kit for convenience, cycle the tank patiently, and resist adding fish until your ammonia and nitrite tests read zero. That four to six week wait is the single most important thing you can do to set your 20-gallon tank up for success. After that, it's regular water changes, consistent feeding, and enjoying a low-maintenance tank that runs well for years.