Lowboy fish tanks for sale turn up at several places: custom aquarium builders, specialty online retailers, secondhand marketplaces, and occasionally at chain pet stores for the smaller sizes. A lowboy is simply a wide, shallow aquarium, shorter in height than a standard tank of the same volume, with a larger horizontal footprint. The look is distinctive, the use cases are specific, and finding one at a good price takes a bit more searching than buying a standard rectangular tank.
If you're looking to buy a lowboy tank, you have three main paths: new from a builder or retailer, used from a local hobbyist or marketplace, or a substitute like a utility tub for non-display purposes. This guide covers all three paths, what to look for during purchase, and which equipment you'll need once the tank arrives.
What Counts as a Lowboy Fish Tank
The term "lowboy" describes shape more than size. A lowboy tank prioritizes width and length over height, typically with water depth in the 10 to 16-inch range instead of the 18 to 24 inches of a standard aquarium.
Common lowboy tank volumes include 10 gallons (24x12x8 inches), 20 gallons long (30x12x12 inches), 29 gallons (30x18x12 inches), and custom sizes ranging up to 150 gallons or more. The 20-gallon long tank is technically a lowboy and is widely available as a standard product. It measures 30 inches long by 12 inches wide by 12 inches tall, and you'll find it at every major pet retailer.
For the true wide-and-shallow configurations above 20 gallons, especially anything custom-sized for turtles, shallow reef builds, or specialty setups, you're entering specialty or custom territory.
Where to Buy a New Lowboy Fish Tank
Chain Pet Stores and Big Box Retailers
For sizes up to 20 gallons, Petco and PetSmart carry the 20-gallon long tank as a standard catalog item, usually in the $40 to $60 range. During Petco's "Dollar Per Gallon" sales (which happen a few times per year), the price drops to $20 for the 20-gallon long. These sales are worth timing a purchase around.
Above 20 gallons, the lowboy configuration disappears from chain store shelves almost entirely. Standard tall tanks dominate the retail floor because they occupy less floor space per gallon, which makes more economic sense for the retailer.
Online Aquarium Retailers
Sites like Aqueon's direct store, Marine Depot, and Bulk Reef Supply occasionally carry lowboy-style tanks, though selection changes seasonally. Aqueon offers a 48-inch standard tank in their standard product line, and while it's not strictly a lowboy in the shallow sense, it provides horizontal footprint.
For purpose-built shallow tanks with specific dimensions, custom aquarium builders are the more reliable source.
Custom Aquarium Builders
Custom Aquariums, Miracles Aquariums, and Planet Aquariums all take orders for non-standard dimensions. A 48x24x12 lowboy in standard 3/8-inch glass runs $250 to $500 depending on builder, features, and whether you want rimless construction. Rimless tanks (no black plastic frames) cost more but look cleaner and are popular for display setups.
Lead times for custom tanks typically run two to six weeks. Factor this into your planning if you're setting up a dated build for a turtle, reptile, or aquatic habitat.
For finding quality gear to go alongside a new tank purchase, browsing the best online fish supply store options helps identify where to source filters, heaters, and substrate at competitive prices.
Where to Buy a Used Lowboy Fish Tank
Used tanks represent significant savings, particularly for hobbyists willing to do some cleaning and resealing work.
Facebook Marketplace
Facebook Marketplace is the most active secondary market for aquariums in most areas. Searching "fish tank," "aquarium," "turtle tank," or "lowboy tank" in your local area surfaces a consistent stream of listings. Pricing varies widely: a 40-gallon breeder (which has a lowboy-adjacent footprint at 36x18x16 inches) regularly appears for $50 to $100 with equipment included.
When buying from Facebook Marketplace, inspect the tank before paying. Check the silicone seams at all corners and edges for cracks, discoloration, or bubbling. Old silicone that's pulling away from the glass is a leak waiting to happen, though it can be repaired with fresh aquarium silicone from any pet store. Also check the glass itself for stress cracks, particularly in the corners.
Craigslist
Craigslist still generates aquarium listings in larger metro areas, though volume has dropped compared to a few years ago. The same inspection process applies. Free tank listings appear occasionally when someone is exiting the hobby and just wants the thing gone.
Local Aquarium Club Sales
Most cities have aquarium clubs that run periodic auctions, swaps, and for-sale postings. These typically list on Facebook groups or forums like Reef2Reef. Club sales tend to attract more serious hobbyists, so equipment condition is often better than random marketplace finds. You're also more likely to get honest information about the tank's history.
Reptile Expos
Since turtles and axolotls are major users of lowboy tanks, reptile and herp expos often have vendors selling appropriate tanks alongside reptile gear. Expo prices are usually retail or near-retail, but you can often negotiate and you get to inspect everything before buying.
What to Check Before You Buy
Whether buying new or used, specific details matter.
Seam condition. On a used tank, every silicone seam needs visual inspection. Run a fingernail along each corner seam. It should feel uniform and firmly attached. Gaps, lifting, or dry-crumbly texture are signs the seam needs replacing before the tank holds water.
Glass stress marks. Hold the tank up to a window or bright light and look for fine cracks, particularly near corners and holes (overflow or bulkhead cutouts). Hairline cracks are invisible when the tank is dark but catch light at certain angles. This is a deal-breaker on a used tank unless you're paying almost nothing for it.
Footprint accuracy. If you have a specific stand, measure the tank carefully before committing. Lowboy tanks have unusual dimensions, and a tank that's an inch wider than your stand's rail spacing won't sit safely.
Included equipment. Used tank listings often include a filter, heater, lights, and stand. Evaluate these separately. Cheap old filters aren't worth using. Lighting from five years ago is probably outdated for a planted or reef setup. But a good canister filter or a functional stand has real value that offsets the tank's purchase price.
Equipment for a Lowboy Fish Tank
Some equipment choices change for a shallow tank.
Heaters: Inline heaters connect between your canister filter's output and the tank, which avoids the issue of standard glass submersible heaters that are too tall for a 12-inch water column. Inline options like the Hydor Theo or the Fluval E series work better in shallow setups. If you do use a submersible heater, mount it horizontally near the substrate.
Filters: Canister filters excel in lowboy setups because they sit outside the tank entirely. The inlet tube needs to be trimmed to fit the reduced water depth. Hang-on-back filters work but are limited to the tank's back rail width and create surface agitation that may not suit all species.
Air pumps: For turtle and axolotl setups where oxygenation matters, a basic air pump like the Tetra Whisper 10 or the Aquatop AP-100 paired with an airstone provides surface agitation and oxygen exchange. The oxygen machine for fish tank options vary by tank size.
FAQ
Where is the cheapest place to buy a lowboy fish tank? Facebook Marketplace and Craigslist consistently offer the lowest prices on used tanks, often 50 to 80 percent below new retail. For new tanks, timing a purchase during Petco's Dollar Per Gallon sale covers smaller sizes well. For custom sizes, prices are fixed by the builder and rarely discounted.
What size lowboy tank is best for a single aquatic turtle? For a hatchling or juvenile (under 4 inches), a 20-gallon long (30x12x12) is adequate. For an adult slider or painted turtle at 6 to 8 inches, aim for at least 75 to 100 gallons in a lowboy or standard breeder format. The common "10 gallons per inch of shell" rule gives you a starting point, and wider is always better than taller for turtles.
Can I reseal a used lowboy tank myself? Yes. Resealing an aquarium requires removing the old silicone with a razor blade and plastic scraper, cleaning the glass edges with rubbing alcohol, and applying fresh 100% silicone aquarium-safe sealant. The most common brand is GE Silicone 1 (clear, not the white mold-resistant version). Let it cure for 48 to 72 hours before filling. It's a two-hour project that extends the life of a cheap used tank by years.
Are lowboy tanks harder to find than standard tanks? Yes, significantly. Above the 20-gallon long size, your options narrow to custom builders, specialty retailers, and secondhand markets. Budget extra lead time if you're building toward a deadline.
Final Thoughts
Finding a lowboy fish tank for sale requires a bit more legwork than buying a standard rectangle, but the options exist at every price point. The 20-gallon long covers smaller budgets at chain stores. Secondhand markets offer good deals on larger configurations with some inspection work. Custom builders handle anything specific you need built to exact dimensions. Once you've sourced the tank, matching it with appropriately sized equipment turns it into a functional setup quickly.