Finding aquarium equipment for sale at a good price means knowing which items are worth buying secondhand and which ones you should always buy new. Used tanks, sumps, stands, protein skimmers, and wave makers are generally safe purchases if you inspect them properly. Heaters, UV sterilizers, and rubber or silicone components are better bought new because failure or degradation isn't always visible.
Whether you're setting up your first tank on a budget or adding equipment to an existing system, there are legitimate ways to spend significantly less than retail without compromising on quality or risking your fish. I'll cover where to find aquarium equipment for sale, what fair prices look like for common items, and what to check before committing to a purchase.
Where to Find Aquarium Equipment for Sale
Online Reef and Aquarium Forums
Reef2Reef's Buy/Sell/Trade (BST) section and The Planted Tank's classified ads are the most reliable online sources for used aquarium equipment. Sellers in these communities have post histories, tank journals, and community reputations that make fraudulent listings rare. Prices are generally fair because both buyer and seller know the market.
On Reef2Reef BST, you'll find listings for protein skimmers, dosing pumps, LED fixtures, reactors, sumps, and complete tank setups. Sellers typically include detailed photos, age of equipment, and reason for selling. For high-value items, most sellers will accept PayPal Goods & Services for buyer protection.
Facebook Marketplace and Reef Groups
Facebook Marketplace has aquarium equipment listed in most metro areas. Prices are often lower than forum listings because sellers want to avoid shipping and deal locally. The tradeoff is less seller context.
Local Facebook reef and freshwater aquarium groups are more useful than general Marketplace because sellers know their equipment's value and buyers can often inspect in person. Search your city name plus "reef club," "aquarium club," or "saltwater fish" to find your regional group.
Craigslist
Craigslist has aquarium equipment listed frequently, especially complete tank setups when people leave the hobby. Prices vary widely. Some sellers list equipment at retail or above, unaware of actual market value. Others list complete setups (tank, stand, filter, light, all accessories) at prices that are genuinely good deals.
Approach Craigslist listings with patience. The good deals exist but require checking regularly.
eBay
eBay has aquarium equipment listings with buyer protection built in. It's particularly good for finding discontinued items or replacement parts (sump baffles, specific powerhead models, older protein skimmer components) that aren't available new anymore.
Buying New vs. Used: Which Equipment Falls Into Which Category
Buy New
Heaters: A failing heater can cook or freeze your fish. Used heaters show few external signs of internal thermostat problems. New heaters from reputable brands (Cobalt Neo-Therm, Eheim Jager, Fluval E-Series) come with a manufacturer warranty and known condition.
UV Sterilizers: The quartz sleeve and UV bulb degrade with use, and internal O-rings can crack. A used UV sterilizer may have a failing sleeve or bulb that's difficult to assess visually.
Air tubing, airline valves, and check valves: These are inexpensive and degrade with time. Always buy these new.
Electrical components with complex controllers: Used GHL Profilucs and similar complex controllers can have firmware issues, failed sensors, or prior water damage that's hard to diagnose without extensive testing.
Buy Used with Inspection
Protein skimmers: Check the pump and needle wheel (covered in more detail in our best protein skimmers section). A quality used skimmer from brands like Reef Octopus, Nyos, or Skimz is a smart purchase.
LED fixtures: Ask to see them running, check LED uniformity, and confirm app connectivity. Quality reef LED fixtures from Kessil, EcoTech Radion, and AI Hydra hold up well.
Aquarium tanks: Glass tanks are nearly permanent if uncracked. Inspect all seams with a flashlight. A thin line of clear silicone along a seam is fine. A crack in the glass itself is not. For used acrylic tanks, look for crazing (tiny surface cracks from UV or chemical exposure) and deep scratches.
Sumps and refugiums: Check for cracks in acrylic and verify all baffles are secure and properly sealed. Smell the interior: strong chemical odors indicate improper cleaning product use that may have contaminated the acrylic.
Wave makers and powerheads: Check that the impeller spins freely and the unit powers on. These are straightforward to inspect and inexpensive to replace if a component fails.
For a curated look at the best equipment across categories, the best aquarium equipment guide covers what's worth buying and what specs matter.
Fair Prices for Common Equipment on the Used Market
These are typical used sale prices from forum BST sections and Facebook groups, based on normal-condition, functional equipment.
Tanks: - 20-gallon standard glass: $15 to $30 - 55-gallon standard glass: $50 to $90 - 75-gallon with stand: $150 to $250 - ADA 60-P (22-gallon rimless): $100 to $160 (new ~$300)
Filtration: - AquaClear 70 HOB: $25 to $40 (new ~$60) - Fluval 307 canister: $80 to $130 (new ~$180) - Reef Octopus Classic 150-INT skimmer: $80 to $120 (new ~$200) - Bubble Magus Curve 7: $55 to $90 (new ~$160)
Lighting: - Kessil A360X: $200 to $280 (new ~$450) - EcoTech Radion G5 Pro: $300 to $400 (new ~$650) - AI Hydra 32 HD: $130 to $180 (new ~$280) - Fluval Plant 3.0 (36-inch): $80 to $130 (new ~$180)
Heaters (new only recommended): - Eheim Jager 100W: $25 to $35 new - Cobalt Neo-Therm Pro 150W: $45 to $60 new
For current pricing on new equipment across categories, the top aquarium equipment page includes current retail price ranges.
How to Inspect Used Equipment Before Buying
Arrive to any in-person purchase with this checklist:
For tanks: Bring a flashlight. Inspect each seam at close range. Look for water stains outside the silicone (indicating a past leak). Fill with water if the seller allows, and check for any seepage.
For filters: Ask to run it in a bucket of water for 10 minutes. Canister filters should prime and flow without air pockets. HOB filters should run quietly.
For protein skimmers: Run in a bucket of water with a small amount of dish soap added (one drop) to simulate the foaming action. The neck should produce foam within a few minutes. Ask to see the impeller removed if possible.
For LED fixtures: Run at full white spectrum and examine each LED. Dim or dark clusters indicate dead LEDs. Run the app and verify full channel control.
For all equipment: Look for corrosion, cracking, and evidence of poor storage (mold, salt damage, dried algae).
FAQ
Is it legal to resell aquarium equipment? Yes, reselling used personal property is legal. The only exception would be certain controlled medications or equipment with export restrictions, which are uncommon in hobby aquarium equipment.
What's the best way to ship aquarium equipment I've purchased online? Most equipment ships well with double-boxing and foam padding. Glass items (protein skimmer necks, specimen containers, glass aquariums) need foam or bubble wrap on all sides with at least 2 inches of padding. Always get tracking and consider insurance for items over $50. LED fixtures should have the driver and optic components wrapped separately from the heat sink.
How do I negotiate on used aquarium equipment? For forum and Facebook sales, it's normal to offer 5 to 15 percent below the asking price, especially if you're picking up locally (saving the seller packaging and shipping effort). Lead with a genuine offer and a reason ("I can pick up this weekend if you'll do $X"). Don't lowball aggressively on reef forums where sellers know market value.
What should I do if used equipment fails shortly after purchase? For forum sales with PayPal G&S protection, you can open a dispute within 180 days. For cash-and-carry local sales, there's typically no recourse. Before completing a local transaction, test anything electrical and confirm it powers on correctly. Some sellers offer a short return window; ask beforehand if this is available.
Wrapping Up
The used aquarium equipment market is genuinely good for buyers who do their homework. Stick to reputable brands, inspect in person when possible, and test electrical components before paying. Buy heaters, UV sterilizers, and airline components new. Everything else, tanks, filters, skimmers, lights, wave makers, is fair game if you verify condition. A patient approach to forum BST sections and local reef groups can outfit a quality reef or planted tank at 40 to 60 percent of what the same equipment costs retail.