Setting up a saltwater fish tank requires a specific set of supplies that differ significantly from freshwater setups. The core list includes a tank, protein skimmer, heater, thermometer, powerhead or wave maker, live rock or ceramic biological media, quality salt mix, a refractometer for salinity testing, and an RODI water system or source. Add lighting matched to whether you're keeping coral, and a test kit for ammonia, nitrite, nitrate, pH, and (for reef tanks) calcium and alkalinity. That covers the essentials. What you add beyond that depends on your livestock goals.
This guide walks through every major supply category in a saltwater setup, explains what each item does, and gives you specific product examples at different price points.
Tanks and Enclosures
Most saltwater setups use glass tanks, which are scratch-resistant and hold optical clarity over time. Acrylic tanks are lighter and insulate better, but scratch during cleaning and are harder to source in standard sizes.
All-in-One Tanks
All-in-one (AIO) tanks like the Waterbox Cube 20, the Innovative Marine Nuvo Fusion 30L, and the Fluval Sea Evo are popular for beginners and small reef systems. They include integrated filtration chambers that hide equipment behind or below the main display. The Innovative Marine Nuvo 30L is particularly well-regarded because the back chambers are deep enough to fit a small protein skimmer and refugium simultaneously.
Standard Glass Tanks
If you're building a custom setup, standard glass tanks from Aqueon or Marineland paired with a separate sump are more flexible. A 75-gallon Marineland with a 20-gallon sump beneath the stand is a common starter reef configuration.
Filtration Equipment
Filtration in a saltwater tank uses live rock (biological), protein skimming (organic removal), and mechanical media (filter socks or pads) rather than the canister-heavy approach common in freshwater.
Protein Skimmers
The protein skimmer is the most important filtration purchase in a saltwater tank. It removes dissolved organic compounds before they enter the nitrogen cycle.
For tanks up to 75 gallons, the Reef Octopus Classic 110 is one of the best-reviewed mid-range skimmers. It runs a needle wheel pump, produces consistent skimmate, and handles the organic load of a moderately stocked reef. The Aqua Remora C (for tanks up to 75 gallons) is a hang-on-back option that works without a sump.
For larger systems, the Bubble Magus Curve 7 handles tanks up to 200 gallons and is a popular choice among intermediate reefers upgrading from a smaller skimmer.
Live Rock and Biological Media
Live rock (or ceramic/dry rock for those avoiding the shipping of wet rock) is colonized by nitrifying bacteria and forms the backbone of biological filtration. The recommended starting amount is 1 to 1.5 pounds of live rock per gallon, though denser, more porous rock can work at lower ratios.
Ceramic biological media like the Brightwell Aquatics NeoMedia Heavy or MarinePure Gems can supplement or replace traditional rock in smaller tanks or sumps.
Filter Socks and Filter Pads
A 200-micron filter sock placed on the overflow drain catches large particles before they reach the sump. Empty and rinse every 3 to 7 days, or detritus accumulates and becomes a nitrate source. Reusable filter socks are more economical than disposable filter pads over time.
Circulation and Flow
Saltwater fish and coral need significantly more water movement than most freshwater species. Aim for 10 to 20 times the tank volume in hourly turnover for a reef tank.
Wave Makers
The Hydor Koralia Evolution 1050 is a solid mid-range option for tanks in the 50 to 120-gallon range. It mounts via magnet on the glass and produces a broad, pulsed flow pattern.
For higher-end setups, the Ecotech Marine Vortech MP10 (for tanks up to 50 gallons) and MP40 (for 50 to 200-gallon tanks) are the premium standard. The Vortech mounts with the motor completely outside the tank, which reduces heat input into the water. These run $250 to $350 each.
The Maxspect Gyre XF280 creates a cross-tank flow pattern that's especially effective at eliminating dead spots in longer rectangular tanks.
Heating and Temperature Control
Most reef tanks run between 76°F and 80°F. Two smaller heaters running in tandem are safer than one large heater because a single heater failure is less likely to spike or crash the temperature catastrophically.
The Eheim Jager TruTemp 150W and 250W are among the most reliable heaters in the hobby. They're calibrated accurately and hold temperature within 0.5°F.
Pairing any heater with an Inkbird ITC-306A temperature controller adds a failsafe layer. The controller monitors the actual water temperature and cuts power to the heater if it overshoots the set point, regardless of the heater's built-in thermostat. At around $30, it's low-cost insurance.
Salinity Management
Saltwater tanks need to be maintained at a specific gravity of 1.025 to 1.026 (approximately 35 ppt) for most fish and coral.
Salt Mix
For fish-only or FOWLR tanks, Instant Ocean is a reliable, cost-effective salt mix that's been the hobbyist standard for decades. For reef tanks where you want elevated calcium, alkalinity, and magnesium levels, Red Sea Coral Pro Salt and Tropic Marin Pro-Reef are formulated with enhanced trace elements. Expect to pay roughly $0.40 to $0.80 per gallon of mixed saltwater depending on brand.
Measurement Tools
A swing-arm hydrometer is cheap but inaccurate. A manual optical refractometer costs $15 to $25 and gives reliable readings when properly calibrated with RODI water. For the most accurate readings, the Milwaukee MA887 digital refractometer reads directly in salinity ppt and is accurate to 0.1 ppt.
For supplies comparison across everything from test kits to sumps, the Best Online Fish Supply Store guide reviews where to get the best selection.
Lighting
Lighting requirements vary dramatically between fish-only tanks (minimal light is fine) and reef tanks (light drives coral photosynthesis and is one of the most important variables in coral health).
For Fish-Only and FOWLR Tanks
Any decent LED fixture producing white and blue spectrum works. The Nicrew ClassicLED Plus and the Current USA Satellite Freshwater Plus LED can work in a pinch for FO tanks, though marine-specific fixtures look better over saltwater due to their blue spectrum emphasis.
For Reef Tanks (Soft Coral and LPS)
The Kessil A160WE Tuna Blue, the VIPARSPECTRA P1000, and the Aqua Illumination Prime 16HD are all popular choices in the $80 to $250 range. The AI Prime 16HD is particularly well-suited for tanks under 24 inches wide and offers spectrum control via an app.
For SPS (Small Polyp Stony) Coral
SPS coral needs higher PAR (photosynthetically active radiation) than soft coral or LPS. The Radion XR15 G5 Pro and the Kessil A360X are the most-referenced lights for this application. Expect to pay $400 to $600 per unit.
Water Testing Supplies
Weekly testing is standard during the nitrogen cycling phase. Once the tank is established, bi-weekly or monthly testing is typical for stable systems.
The API Saltwater Master Test Kit covers ammonia, nitrite, nitrate, and pH. For reef tanks, add alkalinity (dKH), calcium, and magnesium testing to the list. The Hanna Instruments HI772 alkalinity checker and the Salifert or Elos calcium test kits are well-regarded for accuracy at reasonable prices.
For RODI water systems, a TDS (total dissolved solids) meter lets you verify that the membrane is performing. A reading above 5 to 10 ppm at the deionizer stage indicates the membrane or DI resin needs replacement.
The Best Oxygen Machine for Fish Tank Price article covers aeration options that support both freshwater and saltwater setups.
RODI Water and Top-Off Systems
Tap water contains phosphates, silicates, chlorine, and other compounds that fuel algae and stress coral. Using RODI water is standard practice for reef tanks and strongly recommended even for fish-only saltwater setups.
A 5-stage RODI unit like the APEC RO-90 or the SpectraPure MaxCap produces near-zero TDS water. Pair it with an automatic top-off (ATO) system like the Tunze Osmolator 3155 or the IceCap ATO to automatically replace evaporated water and maintain stable salinity.
Evaporation from saltwater tanks can exceed 1 to 2 gallons per day depending on tank size and ambient conditions. Without an ATO, salinity creeps up slowly between manual top-offs.
FAQ
What's the minimum tank size for a saltwater setup? Technically you can run a saltwater fish-only nano tank in 10 gallons, but stability is difficult at that volume. Temperature and salinity fluctuate quickly with small water volumes. Most experienced hobbyists recommend starting with at least a 20 to 30-gallon tank for fish-only setups and 40+ gallons for reef.
How long does it take to cycle a saltwater tank? A standard cycling process takes 4 to 8 weeks without a cycle accelerator. Using Dr. Tim's Aquatics One and Only live bacteria or Brightwell Aquatics MicroBacter7, many tanks cycle in 2 to 4 weeks. Seeding new tanks with an established rock from a running tank is the fastest method.
Do I need a sump for a saltwater tank? No, but a sump significantly improves water stability, hides equipment, and gives you space for a protein skimmer and refugium. For tanks under 40 gallons, hang-on-back skimmers and AIO filtration chambers are a reasonable substitute.
How much does a complete starter saltwater setup cost? A basic 30-gallon fish-only saltwater setup runs $300 to $600 including tank, heater, skimmer, powerhead, salt, and testing supplies. A 75-gallon reef system with quality lighting, a sump, and a good skimmer is more realistically $1,500 to $3,000+ depending on the coral you want to keep.
Conclusion
The most important saltwater fish tank supplies to get right are your protein skimmer, your salt mix, and your water source. Buy RODI water or a unit to make your own, invest in a quality skimmer that's appropriately sized for your tank, and use a name-brand marine salt. Everything else can be optimized over time. Add coral gradually, test water regularly for the first few months, and resist the urge to add too much livestock before the tank has matured for at least 8 to 12 weeks.