Setting up a saltwater aquarium requires more specialized supplies than a freshwater tank, but the core list is manageable. You need a tank, a protein skimmer, a quality salt mix, a refractometer, live rock, a heater, a powerhead for circulation, and a filtration system. Beyond that starter list, reef tanks add lighting and dosing equipment, but fish-only systems can stay relatively simple.

This guide covers every category of saltwater fish supply you'll encounter, from the non-negotiable basics to the equipment you can add over time. I'll include specific product names throughout so you know what to search for rather than just what category to shop in.

The Non-Negotiable Supplies for Any Saltwater Tank

The Tank

Marine fish need more volume than equivalent freshwater setups. The minimum tank size most experienced hobbyists recommend for a first saltwater aquarium is 30-40 gallons. Smaller tanks are harder to stabilize chemically, and water quality problems happen faster and with less warning.

Glass tanks are the standard. Acrylic is lighter and has better optical clarity but scratches more easily. For most hobbyists, a glass rimless or standard glass aquarium is the practical choice.

All-in-one tanks like the Innovative Marine Nuvo 30L or the Waterbox Cube 20 come with filtration chambers built in and are popular for first reef setups because they eliminate the need to buy a sump.

Salt Mix

This is what turns your tap water (after dechlorination) into synthetic seawater. Target a specific gravity of 1.025-1.026 for reef tanks and 1.023-1.025 for fish-only systems.

The most used salt mixes: - Instant Ocean: The budget-reliable choice. Mixes consistently, low in some trace elements but works well for fish-only tanks. - Red Sea Coral Pro Salt: Higher in alkalinity, calcium, and magnesium. More expensive but a better baseline for reef tanks that need stable parameters. - Brightwell Aquatics NeoMarine: Consistent batch-to-batch, popular in competitive reef keeping circles.

A 50-pound bucket of Instant Ocean makes approximately 175 gallons of saltwater at 1.025 salinity.

Refractometer

You need a way to measure salinity. Don't use a swing-arm hydrometer. They're inaccurate, drift over time, and give false readings when air bubbles are present. A basic optical refractometer costs $20-40 and gives you accurate specific gravity readings when calibrated with a reference solution.

The Milwaukee Instruments MA887 or the American Marine Pinpoint Refractometer are both reliable choices. Calibrate with a standard solution (Red Sea Calibration Solution or similar) before each use.

Protein Skimmer

A protein skimmer removes dissolved organic compounds from the water column before they break down into nitrate and phosphate. For saltwater fish tanks, this is the most important piece of filtration equipment you can add.

Entry-level skimmers for small tanks include the Aqua C Remora (hang-on-back, rated to 75 gallons, excellent for the price), the Reef Octopus BH-100 (in-sump or in-chamber, reliable), and the Simplicity 120DC (in-sump, rated for tanks up to 120 gallons).

Heater

Marine fish need stable temperatures in the 76-80°F range. A quality submersible heater with accurate temperature control is non-negotiable.

The Cobalt Aquatics Neotherm is the most-recommended heater in the saltwater hobby for tanks under 75 gallons. Available in 25W, 50W, 75W, 100W, and 150W versions. The Eheim Jager is another reliable choice with a longer track record in the hobby. Avoid cheap unbranded heaters. A heater failure that overheats a saltwater tank can kill an entire system worth hundreds of dollars in livestock.

Circulation and Flow Equipment

Powerheads and Wave Makers

Marine fish and corals need significant water movement, more than most freshwater setups. A general target for reef tanks is 20-30x tank volume per hour in total flow. For a 50-gallon reef, that's 1,000-1,500 GPH of combined circulation.

Wave makers create randomized surge patterns that more closely simulate ocean conditions. The Aquarium Ecotech Marine MP10 and MP40 are the premium options with app control and preset flow patterns. Budget-friendly alternatives include the Jebao SLW-10 and the Hygger Wavemaker series.

For fish-only tanks, a single powerhead providing 10-15x turnover is usually sufficient.

Return Pump

If you're running a sump, you need a return pump to push water back up to the display tank. A DC-powered variable-speed pump gives you control over flow rate. The Ecotech Vectra, Jebao DCP series, and CoralVue Hydros Wave pumps are popular in this category.

Water Testing Supplies

This is an area where shortcuts create problems. You need accurate test kits for:

  • Ammonia and nitrite: Essential during the cycling phase. API Freshwater/Saltwater Master test kit covers these.
  • Nitrate: Ongoing monitoring. Salifert Nitrate test kit is more accurate than API for low-level reading.
  • Alkalinity: For reef tanks, this is the most critical parameter. Salifert or Hanna Instruments colorimeters.
  • Calcium and Magnesium: Reef tank parameters that need monthly testing. Salifert is the hobby standard.
  • Specific Gravity/Salinity: Covered by your refractometer.

For fish-only tanks, you can skip the reef chemistry tests (alk, calcium, magnesium) and focus on the nitrogen cycle parameters.

Lighting

For Fish-Only Tanks

Basic LED strips or T5 fluorescent lights designed for aquarium use are sufficient. You're not trying to grow corals, so the focus is on displaying the fish attractively. Marineland LED Single Bright, Current USA Satellite, and many budget LED bars work fine.

For Reef Tanks

Reef lighting is one of the largest investments in a reef system. SPS corals need intense light in specific spectra (primarily blue 420-450nm and white 6500K). Popular reef LEDs:

  • AI Prime 16 HD: $179, covers tanks up to 24" x 24". Excellent for nanos and small reefs.
  • Kessil A360X: $499, premium quality with intense shimmer effect, covers up to 36" x 36".
  • Hydra 32 HD: $369, programmable with app, excellent PAR output for mid-size tanks.
  • Radion XR15 Pro: $599, the flagship premium option with best-in-class spectrum and control.

For a more comprehensive supply comparison, see our Best Online Fish Supply Store guide.

Chemical Additives and Water Treatment

Dechlorinator

Always use dechlorinator when adding tap water to a marine system. Seachem Prime is the standard: it detoxifies chlorine, chloramine, and temporarily binds ammonia. Use it with every water change and top-off.

Beneficial Bacteria

During the cycling phase, adding a bottled bacteria product speeds the process. Seachem Stability, API Quick Start, and Fritz TurboStart 900 are reliable. TurboStart in particular has strong hobbyist reviews for rapid cycle acceleration.

Reef Additives

For reef tanks, you'll eventually need to dose: - Alkalinity: Two Little Fishies C-Balance, Seachem Reef Builder, or a kalkwasser solution - Calcium: Part of the two-part system above, or calcium chloride - Magnesium: Seachem Reef Advantage Magnesium or similar

Many reef keepers graduate to an automatic dosing pump (Kamoer or CoralVue DoseVue) once manual dosing becomes tedious. For information on oxygenation equipment, see our oxygen machine for fish tank price guide.

FAQ

What's the minimum budget to set up a basic saltwater fish tank? A basic 30-40 gallon FOWLR setup (tank, stand, salt, live rock, heater, powerhead, basic filtration, lighting) can be assembled for $400-700 using a mix of new and used equipment. Adding a protein skimmer and a quality refractometer adds another $60-120. A reef tank with corals and appropriate lighting starts around $700-1,000 for the equipment alone before livestock.

Can you use regular gravel for a saltwater tank? You can use aragonite sand (calcium-based, buffering) which is the standard substrate for saltwater tanks. Plain freshwater gravel doesn't buffer pH and provides no benefit. Crushed coral and aragonite are the better choices. A 4-5" deep sand bed can also host beneficial bacteria and beneficial organisms like copepods.

How often do you need to do water changes on a saltwater tank? 10-15% weekly is the standard recommendation for reef tanks. Fish-only tanks with good filtration can sometimes go bi-weekly. Water changes replenish trace elements and dilute accumulated nitrate and phosphate. Some advanced reef keepers use automated water change systems (Aquafresh or similar) for consistency.

What fish are easiest for a first saltwater tank? Ocellaris clownfish (Nemo) are the classic beginner fish: hardy, adaptable to a range of water conditions, and available captive-bred from multiple sources. Dartfish (firefish, purple firefish) are peaceful and hardy. Royal grammas, six-line wrasses, and chromis damselfish are also commonly recommended for beginners. Avoid angelfish, tangs, and lionfish for first tanks.

Building Your Supply List

Start with the essentials: tank, salt mix, refractometer, protein skimmer, heater, and a basic powerhead. Get the tank cycled before buying any livestock. Add lighting last, since the type of lighting you need depends on what you plan to keep. Rushing to add corals before the tank is stable is the most common beginner mistake, and it's an expensive one. Give yourself 4-6 weeks of cycling and stable parameters before adding any fish or coral.