Salt water tank accessories are everything beyond the core tank itself: the tools, devices, and add-ons that maintain water quality, support livestock health, and simplify maintenance. The essential list includes a protein skimmer, refractometer, powerheads, test kits, and a reliable heater. Beyond those basics, the right accessories depend on whether you're keeping fish-only, soft corals, or a full SPS reef.
Setting up a marine tank requires more deliberate equipment selection than freshwater. Every item in the tank either adds or removes heat, affects water chemistry, or interacts with your livestock in some way. I'll walk through every major category of saltwater tank accessories, what each one does, what to spend, and which specific products are worth considering.
Water Quality Accessories
Water quality testing is the foundation of saltwater keeping. Without accurate readings, you're reacting to problems after they've already caused damage instead of catching them early.
Refractometers
Salinity is the parameter you'll test most often in a salt water tank. A refractometer gives you an accurate specific gravity and salinity reading from a few drops of water. The Milwaukee MA887 (~$30) with ATC (automatic temperature compensation) is accurate enough for any home aquarium. Swing-arm hydrometers are significantly less reliable, with readings that can be off by 0.002-0.004 specific gravity due to sticky pivots and calibration drift.
If you want even more precision, digital refractometers like the D-D H2Ocean Pro ($80) eliminate parallax error and are worth the upgrade for reef tanks where even minor salinity swings matter.
Test Kits
For a fish-only saltwater tank, the API Saltwater Master Test Kit ($35) covers pH, ammonia, nitrite, and nitrate. For a reef tank, you'll additionally need calcium (target 400-450 ppm), alkalinity (8-12 dKH), and magnesium (1250-1350 ppm) tests. Salifert individual kits are the hobby standard for accuracy. ICP (inductively coupled plasma) testing through services like ICP-OES from Triton or ATI runs $35-$50 per test and gives you a complete panel of 30+ elements, which is useful once or twice a year for catching trace element imbalances.
Electronic Monitoring
Continuous monitoring systems like the Neptune Systems Apex ($450-$650) track pH, temperature, salinity, and other parameters in real time with phone alerts. For most hobbyists, a standalone digital pH meter (Milwaukee MW102, ~$60) and a separate temperature controller (Inkbird ITC-306A, ~$35) provide most of the protection at a fraction of the cost.
Filtration Accessories
Protein Skimmers
A protein skimmer is the most impactful single accessory for a salt water tank. By pulling dissolved organics out before they cycle into ammonia and nitrate, a skimmer reduces your maintenance burden and keeps the tank cleaner between water changes. Size the skimmer for 1.5x to 2x your actual system volume for best results.
The Reef Octopus Classic 100-INT ($130-$150) is a reliable in-sump option for tanks up to 100 gallons. The Aqua Remora Nano HOB Protein Skimmer ($80-$100) works without a sump and handles tanks up to 40 gallons. For a comparison of available skimmer options at different price points, the Best Freshwater Aquarium Accessories guide also reviews skimmer crossover products.
Carbon and GFO Reactors
A media reactor lets you run activated carbon (removes yellowing compounds and odors) or GFO (granular ferric oxide, which removes phosphate) in controlled flow. The BRS Dual Reactor ($75) handles both media types simultaneously and is compatible with most sumps and return pump setups.
Filter Socks and Mechanical Media
Filter socks (100-200 micron felt) catch particulate matter entering the sump from the overflow. Cleaning or replacing them every 3-5 days prevents trapped detritus from leaching nitrates back into the system. A 4-inch felt filter sock fits most standard sump overflow baffles.
Circulation and Flow Accessories
Powerheads
Koralia powerheads (Hydor brand) remain one of the most reliable options in the hobby. The Koralia Nano 240 (for nano tanks), Koralia 1150, and Koralia Evolution 2400 cover the range from small to large systems. They're quiet, have low failure rates, and don't require maintenance beyond an occasional cleaning.
For wave simulation, the Jebao SLW-10 ($40) and SLW-20 ($55) produce randomized flow patterns via a wireless controller, which corals respond to better than steady directional current.
Wave Makers
High-end wave makers like the EcoTech Marine MP10QD ($230) and Tunze Turbelle Stream 6055 ($180) are worth the premium for SPS reef tanks where flow quality directly affects coral health and growth. The EcoTech Mobius app integration allows sophisticated programming of flow patterns that mimic tidal cycles and storm surges.
Heating and Temperature Accessories
Heaters
The Eheim Jager heater is a dependable, accurate heater used across thousands of aquariums. The 150W model handles up to 40 gallons, and the 300W covers up to 100 gallons. Running two heaters at half the required wattage each gives you redundancy: if one fails off, the other maintains temperature; if one fails on, the second controller stops it before the tank overheats.
Temperature Controllers
An external temperature controller like the Inkbird ITC-306A ($35) provides a safety net that your heater's built-in thermostat cannot. The probe monitors actual water temperature and cuts power if a set maximum is exceeded, preventing heater malfunction from killing your livestock.
Auto Top-Off Systems
Saltwater evaporates, but salt doesn't. Without daily top-offs with fresh RODI water, salinity creeps up steadily. During summer, a 75-gallon tank can lose 1-2 gallons per day. An auto top-off system (ATO) automates this.
The Tunze Osmolator 3155 ($130) is considered the gold standard for reliability. It uses dual-level optical sensors and shuts off automatically if a sensor fails to prevent flooding. The Innovative Marine HydroFill ATO ($60-$80) is a simpler, more affordable option for smaller systems.
Lighting Accessories
Mounting and Hanging Hardware
Hanging your main light above the tank on a mounting arm (rather than resting it directly on the rim) improves PAR distribution and reduces heat transfer to the water. The AI Flex Arm ($50) works with the AI Prime series. Universal hanging kits from Kessil and Rapid LED accommodate different fixture types.
Refugium Grow Lights
A refugium light over your sump's macroalgae section helps chaeto or other nutrient-exporting algae grow and outcompete nuisance algae in the display tank. The Kessil H80 Tuna Flora ($70) is the most frequently recommended option for refugiums up to 20-25 gallons in the sump.
Maintenance Accessories
Magnetic Glass Cleaners
The Flipper Magnet Standard ($25-$35) and Tunze Care Magnet ($30-$60) are top-tier options for keeping the glass clear without getting your hands wet. Select the correct model for your glass thickness (the Flipper Nano works to 6mm, the Standard to 12mm).
Siphons and Water Change Tools
Python No Spill Clean and Fill ($30-$55) attaches to your faucet and makes water changes a one-person job without bucket handling. For reef tanks where RO/DI water is used for water changes, a separate RO/DI unit (like the BRS 4-stage RO/DI at $200) pays for itself quickly compared to buying premixed saltwater.
For current pricing and the best places to buy accessories, the Best Buy Aquarium Accessories Online guide covers both Amazon and specialty aquarium retailers.
FAQ
What salt water tank accessories should I buy first? Prioritize in this order: refractometer, protein skimmer, test kits (Salifert or API), and at least one powerhead. These four items address salinity measurement, organic waste removal, water chemistry monitoring, and circulation. Everything else can come after those are in place.
Do I need a UV sterilizer for a saltwater tank? Not essential, but useful if you have repeated outbreaks of ich or other parasites. A UV sterilizer like the Coralife Turbo-Twist 12X ($120) or the Aqua Ultraviolet Advantage 15W ($150) kills free-floating pathogens and algae spores as water passes through the unit. It won't eliminate ich from the substrate or live rock, but it reduces the free-swimming stage significantly.
How much should I budget for salt water tank accessories? For a 55-gallon fish-only setup, budget $300-$500 for accessories beyond the tank and main equipment. A reef tank of the same size typically needs $500-$1,000 in accessories, driven primarily by coral-specific needs like dosing equipment, a refugium light, and wave makers.
What accessories are specific to reef tanks vs. Fish-only tanks? Reef-specific accessories include a dosing pump or calcium reactor (to replace consumed calcium and alkalinity), a refugium light, a wave maker (rather than a simple powerhead), and more precise testing equipment for calcium, alkalinity, and magnesium. Fish-only tanks can get by with simpler filtration, basic powerheads, and standard test kits.
Conclusion
The priority for salt water tank accessories is stability and water quality first. Start with a refractometer, protein skimmer, accurate test kits, and circulation pumps. Add an auto top-off system and temperature controller next. Dosing equipment, refugium lighting, and advanced monitoring come after the core system is dialed in. Each accessory you add should be solving a specific problem or reducing a maintenance task, not just adding complexity.