Selling a used fish tank is straightforward once you know where to look and how to price it. The short answer: local Facebook Marketplace and Craigslist listings move tanks fastest, while specialty forums and aquarium club groups get you better prices for high-end setups. This guide covers where to list, how to price, what to include in your post, and how to avoid the most common mistakes sellers make.
Whether you're upgrading to a bigger tank, downsizing, or getting out of the hobby entirely, there's a real market for used aquarium equipment. People pay good money for quality glass, complete setups, and working filtration gear. You just need to present it right.
Where to Sell Your Used Fish Tank
Local Marketplaces
Facebook Marketplace and Craigslist are where most used fish tanks actually sell. Large tanks are heavy and expensive to ship, so local pickup is almost always how these deals work. A 55-gallon tank with a stand routinely sells for $100-$200 locally when new it would cost $400 or more.
Post in your city plus surrounding suburbs. Someone will drive 45 minutes to pick up a good deal on a complete reef setup. Put your general location in the listing so buyers can estimate the drive.
Nextdoor works well too, especially for smaller tanks (10-20 gallons) that appeal to parents setting up a child's first tank.
Aquarium-Specific Groups and Forums
For specialty gear, reef setups, or expensive equipment, aquarium groups get you more money and more serious buyers:
- Facebook aquarium groups: Search for groups like "Aquarium Buy Sell Trade [Your City/State]" or national groups like "Aquarium Equipment Buy Sell Trade." Members know what things are worth and will pay accordingly.
- Reef2Reef Marketplace: If you're selling reef equipment, this forum has active buyers who understand value. A used Kessil A360 or an EcoTech Vortech pump will sell here for close to market rate.
- The Planted Tank (TPT) Forum: Great for planted tank equipment, CO2 setups, and lighting.
- Local aquarium clubs: Many cities have aquarium societies that host swap meets or have member classifieds. You'll skip fees and find knowledgeable buyers.
Specialty Resale Sites
eBay works for smaller, shippable items: filters, heaters, powerheads, test kits. You can reach national buyers and often get more than local prices. Factor in about 13-15% for fees plus shipping costs before you price anything.
Offerup is another option worth posting on alongside Craigslist.
How to Price a Used Fish Tank
Pricing used aquarium equipment follows a rough formula: complete setups with working equipment go for 40-60% of new retail. Tanks sold bare (no stand, no lid, no filter) drop to 20-30% of new.
Pricing by Tank Size
- 10-gallon tanks: $15-$30 bare, $40-$75 with filter, heater, and lid. These sell fast because they're affordable starter setups.
- 20-gallon tanks: $30-$60 bare, $75-$150 complete.
- 40-55 gallon tanks: $80-$150 bare, $200-$400 complete with good equipment.
- 75-100+ gallon tanks: $200-$500+ bare depending on glass thickness and brand. Complete setups with sumps, skimmers, and lighting can reach $800-$2,000.
Adjusting for Condition
Scratches matter a lot. Light surface scratches are expected; deep scratches on the front panel kill deals. If the tank has significant scratching, either price it low ($15-$30 below comparable tanks) or be upfront that it's suited for a sump, quarantine setup, or a buyer who will keep it against a wall.
Custom or name-brand tanks hold value better. An Aqueon or All Glass tank from the big box store loses value quickly, but a Elos, Rimless Aquariums, or custom built acrylic tank from a specialty shop is worth researching separately.
What to Include in Your Listing
A good listing photo and description makes the difference between getting messages and getting ghosted.
Photos That Actually Help
Take photos in good lighting, ideally with the tank clean and dry. Include: - Front panel close-up showing any scratches - Full tank from 3/4 angle showing stand if included - Individual equipment photos (filter, heater, pump, lights) - Sump photos if selling a complete reef setup - Any cracks or damage, even minor ones (disclose everything)
What to Write in Your Description
State everything that's included. Buyers want to know: tank dimensions and gallons, stand included or not, filter model and size, heater brand and wattage, lighting (type and bulb age), whether the substrate is included, and any livestock if you're selling them separately.
Example: "55 gallon Aqueon glass aquarium (48"x12"x21") with black metal stand, Fluval 307 canister filter (2 years old, works perfectly), Eheim Jager 200w heater, Nicrew LED light. No livestock. Local pickup only, cash or Venmo."
That listing answers every question a buyer has before they ask.
Selling Livestock Separately
Most platforms don't allow selling live fish. Keep livestock listings in aquarium club groups or forums where it's specifically allowed. Selling livestock and equipment separately also simplifies the transaction for equipment buyers.
Cleaning and Preparing Your Tank for Sale
A clean tank sells faster. Empty it completely, remove all substrate, wipe down the glass with a razor blade for algae (not metal on acrylic), and let it dry. Run the filter one last time to confirm it works, then describe exactly what you did.
For saltwater tanks, a thorough rinse is worth the effort. Residual salt creep and dried coralline algae look bad in photos and concern buyers about the tank's history.
Don't use soap or household cleaners. If the tank smells like anything other than old water, buyers get nervous.
Handling the Transaction and Pickup
Pricing for Negotiation
List 10-15% above what you'll accept. Buyers almost always offer less, especially on Craigslist. If you want $200, list at $225.
Safety and Payment
Meet during daylight hours. For large tanks, the buyer almost always needs to bring helpers anyway, so you'll have witnesses around. Accept cash or instant payment apps (Venmo, Zelle) only. No checks, no "I'll Venmo you after pickup."
For expensive setups worth $500 or more, get payment before loading equipment.
If the Tank Doesn't Sell
Drop the price 10-15% every two weeks. If it sits for 6+ weeks, consider local aquarium club donations (you'll get goodwill and sometimes store credit), breaking it into parts to sell individually, or reposting in a different season. Spring and fall tend to be busier for aquarium buying.
If you're upgrading and need supplies for your next tank, check what's available at a best online fish supply store before spending on new equipment.
FAQ
Does a used fish tank need to be tested before selling? Yes, and you should tell buyers you've tested it. Fill the tank, let it sit 24-48 hours, and check for leaks. A tank that holds water is far easier to sell. If it leaks, you can either reseal it yourself (silicone resealing is a common DIY fix, costs about $10 in materials) or price it as a "fixer" or planter tank.
What's a fair price for a 55-gallon tank with stand and filter? Expect $150-$250 in most markets for a clean setup with a working Aqueon or Marineland filter and a basic metal stand. If the filter is a higher-end model like a Fluval FX4 or Rena Filstar XP, add $40-$80 to that range. Brand-name stands (Aqueon, Marineland) add more value than generic metal tube stands.
Can I sell a fish tank that has a small crack? Yes, but you must disclose it upfront and price accordingly. A crack that doesn't affect the water-holding panels (back or side panel near the top) might be acceptable to a buyer using it as a vivarium or dry display. A crack in a bottom or front panel is usually a deal-killer for anyone wanting to hold water. Be completely honest or you'll get a very unhappy buyer showing up at your door.
Should I sell the equipment separately or as a complete package? Complete packages sell faster but for less total money. Selling pieces separately takes longer but often returns 20-30% more overall. If you want quick cash, bundle everything. If you're patient and the equipment is quality (Eheim, Fluval, Kessil, EcoTech), selling individual pieces will get you more. If you need to replace gear for your next setup and want to save on aquarium equipment costs, selling piecemeal makes sense to fund the new purchases.
Wrapping Up
The fastest path to selling your used fish tank is a clean, honest listing on Facebook Marketplace with clear photos and a price about 45-50% of what the same setup costs new. For reef equipment or specialty gear, Reef2Reef Marketplace or local aquarium clubs will get you better prices and more knowledgeable buyers. Disclose everything, test the tank before listing, and have a firm (but slightly negotiable) price in mind before you post.