You can buy almost every pet fish supply you need online, often at 20-40% less than retail pet store prices. The best online sources for fish supplies are Amazon (for equipment and dry goods), specialty retailers like Bulk Reef Supply and Marine Depot (for reef equipment and chemicals), and live animal vendors like LiveAquaria and Aquatic Arts (for fish, invertebrates, and plants). The one category where ordering online has real limitations is live animals in warm weather and perishable items like frozen food.
This guide covers the most reliable online sources for fish supplies, what's worth ordering online versus buying locally, how to save money on repeat purchases, and what to watch out for when buying fish supplies from Amazon.
The Best Online Retailers for Fish Supplies
Amazon
Amazon is the default starting point for aquarium equipment and dry goods. Selection is vast, pricing is competitive, and Prime shipping gets most items to you in 1-2 days. For filters, heaters, air pumps, lighting, substrate, and standard fish foods, Amazon pricing beats most brick-and-mortar pet stores by 15-30%.
The main caveat is quality verification. Amazon's marketplace includes third-party sellers alongside Amazon's own stock, and counterfeit or substandard products occasionally slip through for popular items. Stick to brands you recognize (Fluval, Seachem, API, Marineland, Eheim, Tetra, Aqueon) and read reviews carefully. Products with thousands of reviews and 4+ star ratings are generally safe bets.
Subscribe & Save on consumables like fish food, water conditioner, and filter cartridges saves an additional 5-15% and eliminates the need to remember to reorder.
Bulk Reef Supply (BRS)
BRS is the best online source for reef aquarium equipment and chemicals. They carry brands that most pet stores don't stock: Apex controllers, Radion LEDs, GHL equipment, BRS-branded bulk chemicals (two-part, carbon, GFO), and specialty reef media. Their prices on reef chemicals sold in bulk are dramatically lower than retail: a 10-pound jug of BRS Two-Part Part A costs around $20 and equivalent individual one-liter bottles from pet stores would cost $60+.
BRS also runs an excellent YouTube channel with tutorials on reef chemistry, equipment setup, and coral keeping that's worth bookmarking alongside their store.
Marine Depot
Marine Depot is BRS's main competitor in the reef supply space and worth checking for price comparisons. They often have better pricing on specific brands, and their selection of protein skimmers, reactors, and mechanical filtration equipment is strong.
LiveAquaria
LiveAquaria is the most reliable source for ordering live fish and invertebrates online. They guarantee all livestock alive upon arrival and offer a 14-day guarantee on most items. Their selection is far wider than any local fish store: over 2,000 species of freshwater and saltwater fish, invertebrates, and coral.
Shipping live animals adds $30-40 per order for overnight delivery, so ordering multiple animals at once is more economical than individual orders.
Aquatic Arts
Aquatic Arts specializes in freshwater invertebrates (shrimp, snails, crayfish), small specialty fish, and live aquatic plants. They're based in Indiana and ship Monday through Wednesday to avoid weekend delays. Their aquatic plant selection and quality is among the best available online.
eBay and Aquarium Forums
eBay has a significant aquarium section with both new equipment and used gear. Buying used filters, protein skimmers, and lighting from hobbyists on eBay can save 40-60% compared to new prices. The trade-off is no manufacturer warranty and variable condition.
Reef2Reef's buy/sell/trade forum (for saltwater) and the r/AquaSwap subreddit are excellent sources for used equipment and quality livestock from experienced hobbyists. These communities often produce better deals and better-cared-for livestock than eBay.
What to Order Online vs. Buy Locally
Always Buy Online: Equipment
Filters, heaters, protein skimmers, lighting systems, power heads, dosing pumps, controllers, and canister filters are almost always cheaper online than in pet stores. The difference is not trivial. A Fluval 307 canister filter at PetSmart runs $140-150. Amazon's regular price is $100-110, and it drops to $85-95 on sale.
For expensive equipment, use price trackers like CamelCamelCamel (for Amazon) to watch for price drops. Filter systems, reef lights, and protein skimmers regularly go on sale 20-30% below their usual price.
Usually Buy Online: Dry Goods
Substrate, frozen food (from local stores or online with insulated shipping), fish food, water conditioners, test kits, and medications are consistently cheaper online. A 50-pound bag of CaribSea Eco-Complete freshwater substrate is $35 online vs. $50+ in stores. A 500mL bottle of Seachem Prime is $35 online vs. $25 for a much smaller 250mL bottle in stores.
The exception: emergency supplies. If your tank has an ammonia spike at 10pm and your fish are in distress, paying $5 more for a bottle of Prime at PetSmart is worth it. Keep emergency supplies on hand to avoid last-minute trips.
Buy Local: Live Animals (Ideally)
Buying fish locally lets you see their condition before purchase, quarantine properly, and avoid shipping stress. Reserve online livestock orders for species your local store doesn't carry. When you do order live animals, plan the delivery for a time when you can be home to receive them, and have a quarantine tank ready.
For a list of the best vetted online sources for live fish and equipment, check out our guide to the best online fish supply store.
Saving Money on Repeat Purchases
Auto-Delivery Subscriptions
Amazon Subscribe & Save, Chewy's auto-ship program, and Petco's repeat delivery discount all reduce the per-unit cost of consumables by 5-15%. Set these up for fish food, filter cartridges, water conditioner, and test kit reagents.
Chewy in particular is worth setting up for larger pet supplies. They offer free shipping on orders over $49, and their auto-ship pricing on fish food can beat Amazon's Subscribe & Save prices on popular brands like New Life Spectrum, Hikari, and Fluval Bug Bites.
Buying in Bulk
For reef chemistry and water treatments, bulk purchasing from BRS dramatically reduces per-unit cost. Buying a 10-pound tub of BRS Reef Saver carbon versus a small bag from a pet store can reduce cost by 60-70%. For water conditioner, Seachem Prime in the 2-liter bottle versus the 100mL pet store bottle saves about 50% per dose.
The only caveat is shelf life. Most dry aquarium chemicals have 2-3 year shelf lives, so bulk buying makes sense for supplies you'll use within that window.
Timing Purchases Around Sales
Amazon regularly discounts aquarium equipment around Prime Day (July), Black Friday, and during spring and fall aquarium hobby buying seasons. Chewy runs 20-30% off sitewide sales several times a year. Setting up price alerts via CamelCamelCamel for items on your wish list pays off over time.
Ordering Frozen Fish Food Online
Frozen foods like Hikari Mysis Shrimp, San Francisco Bay Brand Brine Shrimp, and various frozen coral foods can be ordered online with insulated shipping, but the economics require ordering in quantity to make shipping cost worthwhile. Most frozen food online vendors require orders of 12-24 cubes minimum to justify the $15-25 overnight cold pack shipping cost.
For most hobbyists with 1-2 tanks, buying frozen food locally at a fish store or Petco (which stocks a decent frozen selection in most locations) is more practical than ordering online. Large reef keepers with multiple tanks who go through several blister packs per week find online bulk frozen food purchasing worthwhile.
For specific product recommendations on aeration and filtration equipment, our guide on oxygen machine for fish tank price covers what to look for and what to pay.
FAQ
Is it safe to buy aquarium equipment from Amazon's third-party sellers? Generally yes for major brands (Fluval, Seachem, Eheim, API) when buying from sellers with established track records and high ratings. Be more cautious with off-brand equipment from new sellers. If a deal looks too good, it often is. For critical equipment like heaters and filters, stick to fulfilled-by-Amazon listings or the brand's direct Amazon storefront.
How does Chewy compare to Amazon for fish supplies? Chewy excels for food, medications, and pet-specific consumables. Their auto-ship program and customer service (famous for sending personalized cards and replacing damaged or defective items without question) are genuinely excellent. Amazon wins on equipment pricing and selection. Most serious hobbyists use both: Chewy for consumables, Amazon for equipment.
Can I order live plants online and will they survive shipping? Yes. Aquatic Arts, Aquarium Co-Op, and several eBay vendors ship live plants successfully. Plants ship better than fish, as they're less sensitive to oxygen levels in transit. Plants arrive submerged in water in sealed bags or wrapped in damp newspaper, and most handle 2-3 days in transit without significant damage. Order from Monday to Wednesday to avoid weekend postal delays.
What's the minimum order to justify shipping costs from specialty reef retailers? Most specialty reef retailers like BRS offer free shipping on orders over $29-49. Placing combined orders that hit that threshold makes online specialty purchasing cost-effective. If you need one item that falls below the free shipping threshold, check Amazon first since they usually stock a wide range of reef supplies too.
Making Online Buying Work for Your Tank
The practical approach: set up repeat delivery for consumables (food, conditioner, test kit reagents), buy equipment online when you have time to compare prices and wait for a sale, keep emergency supplies on hand locally, and shop specialty reef vendors for brands your local store doesn't carry. That combination gets you the best pricing without the frustration of waiting for shipping when your fish need something now.