Setting up a saltwater aquarium requires more specialized equipment than a freshwater tank, but the core supply list is manageable once you understand what each item does. At minimum, you need a tank, a quality protein skimmer, live rock, a heater, a powerhead or circulation pump, a hydrometer or refractometer, marine salt mix, and proper lighting. That's the short answer. The longer answer is that which products you buy, and at what price points, makes a real difference in how stable and healthy your tank turns out.
This guide covers every major category of saltwater aquarium supplies, explains what to prioritize, and gives you specific product examples at different budget levels. Whether you're setting up your first 20-gallon fish-only tank or building a full reef system, you'll find concrete recommendations here.
The Tank and Stand
The tank itself is where everything starts. For saltwater setups, glass tanks are the most common choice because they're scratch-resistant and hold their clarity over time. Acrylic tanks are lighter and offer better insulation, but they scratch more easily during cleaning.
Starter Tanks
The Aqueon 20-gallon standard glass aquarium is a solid entry point for fish-only setups. It's affordable, widely available, and the footprint is manageable. For reef tanks, a 40-gallon breeder gives you better surface area-to-depth ratio, which helps with gas exchange and lighting coverage.
If you want a complete starter package, the Coralife Fish Only Marine Aquarium kit comes with a basic hood and frame, though you'll still need to add a protein skimmer and circulation pump.
All-in-One Tanks
For beginners or small reef setups, all-in-one (AIO) tanks like the Innovative Marine Nuvo Fusion 20 or the Waterbox Cube 20 include integrated filtration chambers behind the main display area. These are worth the premium price because they keep the equipment hidden and reduce the number of separate components you need to purchase.
Filtration: The Most Important Category
Filtration in a saltwater tank typically runs on three levels: mechanical (removing particles), biological (cycling nitrogen), and chemical (activated carbon or other media). Getting this right is what separates a tank that constantly fights algae and poor water quality from one that runs cleanly.
Protein Skimmers
A protein skimmer is non-negotiable for saltwater tanks. It pulls dissolved organic compounds out of the water before they can break down into ammonia. For tanks up to 100 gallons, the Aqua Remora HOB (hang-on-back) skimmer and the Reef Octopus Classic 110 are both well-regarded. The Reef Octopus 110 handles tanks up to about 105 gallons and uses a needle wheel pump, which is quieter and more efficient than older venturi designs.
Sump-based skimmers like the Bubble Magus Curve 5 sit inside a sump filter and are the preferred setup for larger systems. For a 55 to 75-gallon tank, the Curve 5 is appropriately sized.
Live Rock
Live rock is the backbone of biological filtration in a reef or FOWLR (fish-only with live rock) system. It's colonized by bacteria that process ammonia into nitrite and then nitrate. Standard recommendation is 1 to 1.5 pounds of rock per gallon, though this varies based on the porosity of the rock you're using. Aquacultured rock from Florida and other domestic sources has become more common and doesn't carry the same hitchhiker risks as wild-collected rock.
Canister Filters
For fish-only saltwater tanks, canister filters like the Fluval 307 or the Eheim Classic 350 provide solid mechanical and biological filtration. They're less ideal for reef tanks because they can accumulate nitrates if not cleaned regularly, but for fish-only systems they do the job well.
Circulation and Flow
Saltwater fish and coral require more water movement than most freshwater species. Stagnant spots in a reef tank lead to detritus buildup, low oxygen pockets, and unhappy coral.
Powerheads and Wave Makers
The Tunze Turbelle NanoStream 6020 is a compact wave maker rated for tanks up to about 66 gallons and produces a gentle, broad flow pattern. For larger reef tanks, the Maxspect Gyre XF280 creates a cross-tank gyre flow pattern that's particularly effective at reaching low-flow dead zones.
Return Pumps
If you have a sump, you need a return pump to push water back up to the display tank. The Sicce Syncra Silent 3.0 and the Ecotech Marine Vectra M1 are both strong choices. The Vectra M1 runs on DC power and is adjustable via a controller, which lets you dial in exact flow rates.
Lighting
For fish-only saltwater tanks, standard LED fixtures work fine. For reef tanks, lighting requirements get more specific depending on whether you're keeping soft corals, LPS (large polyp stony), or SPS (small polyp stony) corals.
Budget and Mid-Range Reef Lights
The VIPARSPECTRA P1000 and the Mars Aqua 165W LED are popular budget options that cover the PAR (photosynthetically active radiation) requirements for most soft corals and LPS. Expect to pay $80 to $150 for these.
For more demanding SPS systems, lights like the Radion XR15 G5 or the Kessil A360X provide the intensity and spectrum control that coral farms use, though these run $400 to $600 each.
Heating and Temperature Control
Marine fish and coral are sensitive to temperature swings. Most reef tanks are kept between 76°F and 80°F. A quality heater with a reliable thermostat prevents the kind of temperature crash that can wipe out a tank overnight.
Heater Recommendations
The Eheim Jager TruTemp heater is one of the most consistent options in the hobby. The 150-watt version handles tanks up to about 40 gallons, and the 250-watt covers 65 to 80 gallons. For added redundancy, many reef keepers use two smaller heaters instead of one large one. If one fails in the "on" position, a single heater can overheat the tank, but two smaller ones running at lower duty cycles reduce that risk.
The Inkbird ITC-306A is an external temperature controller that plugs into any heater and overrides the built-in thermostat if the water gets above your set point. It's a cheap insurance policy at around $30.
Salinity Measurement and Salt Mix
Getting salinity right matters. Saltwater tanks run at a specific gravity of 1.025 to 1.026 (35 ppt) for most fish and reef applications.
Refractometers vs. Hydrometers
A swing-arm hydrometer is cheap but inaccurate. For a few extra dollars, an optical refractometer gives you a much more reliable reading. The Milwaukee MA887 digital refractometer is a popular choice among serious hobbyists because it reads salinity directly in ppt rather than requiring you to interpret a specific gravity scale.
Salt Mixes
Instant Ocean is the standard entry-level salt mix and covers all the basic ionic requirements for fish-only and FOWLR tanks. For reef tanks that need elevated calcium, alkalinity, and magnesium levels, Red Sea Coral Pro Salt and Tropic Marin Pro-Reef are better options. Both are formulated with elevated trace element concentrations that support coral growth.
Water Testing Supplies
Testing your water regularly is not optional in a saltwater tank. At minimum, you should test ammonia, nitrite, nitrate, and pH weekly during the cycling phase and at least bi-weekly once the tank is established. Reef tanks also need calcium, alkalinity, and magnesium testing.
The API Saltwater Master Test Kit covers the basics at a reasonable price. For more precise alkalinity testing, the Hanna Instruments HI772 checker photometer reads in dKH and is accurate to 0.5 dKH. This level of precision matters for SPS coral, where alkalinity swings of even 0.5 dKH can cause tissue recession.
If you want to look at a comprehensive setup guide covering all this equipment together, the Best Aquarium Equipment roundup covers top picks across all categories.
RO/DI Water
Tap water contains chlorine, chloramines, phosphates, and silicates that fuel algae growth and stress sensitive marine life. Using RODI (reverse osmosis/deionized) water for all top-offs and water changes is one of the most impactful things you can do for water quality.
The APEC Water RO-90 is a reliable 5-stage RODI system that produces water with a TDS (total dissolved solids) reading near zero. The cost per gallon works out to a fraction of buying premixed saltwater from a fish store.
For more equipment picks across the full range of saltwater supplies, the Top Aquarium Equipment guide has specific product comparisons by tank size.
FAQ
How much does it cost to set up a basic saltwater aquarium? A basic 20-gallon fish-only saltwater setup runs about $300 to $500 including tank, heater, protein skimmer, powerhead, salt mix, and testing supplies. A 50-gallon reef system with good lighting is more realistically $800 to $1,500 depending on the coral you want to keep.
Do I need a sump for a saltwater tank? A sump is not required, especially for smaller fish-only tanks. Hang-on-back skimmers and canister filters can handle the filtration load for tanks under 75 gallons. That said, a sump gives you more water volume (which increases stability), a place to hide equipment, and easier access to filtration media.
Can I use tap water for a saltwater tank? Technically yes, but it increases the risk of algae blooms and can stress sensitive fish and coral. Treating tap water with a dechlorinator like Seachem Prime helps, but it doesn't remove phosphates or silicates. For reef tanks especially, RODI water is strongly recommended.
How often do I need to do water changes in a saltwater tank? A typical recommendation is 10% to 20% per week for reef tanks and every 2 to 4 weeks for fish-only setups. More frequent changes help keep nitrates down and replenish trace elements consumed by coral.
Conclusion
The core supply list for a saltwater tank breaks down into a few non-negotiables: quality protein skimmer, live rock or ceramic biological media, a reliable heater with a controller, consistent water circulation, and a refractometer for salinity checks. Don't cut corners on the skimmer or the salt mix. Those two items do more to determine long-term water quality than almost anything else in the system. Start with those, get the tank cycled properly, and add livestock slowly.