Marine Tank Supplies — Aquarium Equipment

Marine tank supplies fall into two categories: the equipment you need to keep saltwater fish and coral alive, and the consumables you go through regularly. The equipment list for a reef or FOWLR (fish only with live rock) tank is more extensive than freshwater, but the core items are a protein skimmer, a return pump, live rock, a reliable heater, a refractometer for salinity measurement, and a quality salt mix. Beyond those foundations, what you need depends heavily on whether you're keeping fish only, a mixed reef, or a high-light SPS coral tank. Each setup has its own list.

This guide covers the core equipment categories for a marine tank, what specific products work well, what each item costs, and how the supply list changes as you move from a basic fish-only tank toward a full reef setup. I'll also cover the consumables you'll need to budget for on an ongoing basis.

Foundation Equipment: What Every Marine Tank Needs

These are the items you can't skip regardless of tank type.

Protein Skimmer

A protein skimmer removes dissolved organic compounds from the water before they break down into ammonia and nitrate. It works by creating fine bubbles inside a contact chamber; organic molecules stick to the bubbles and collect in a collection cup above the water line. For tanks up to 75 gallons, the Reef Octopus Classic 110-SS is a dependable external hang-on skimmer. The Bubble Magus Curve 5 is a popular sump-rated skimmer for similar tank sizes at a lower price point (around $120 to $150). For a 100-gallon display, the Reef Octopus Classic 150-SS or the Skimz Monzter SM127 handles the load.

Skimmers are rated by manufacturer for a "maximum tank size" but these numbers are optimistic. A skimmer rated for 150 gallons typically performs well on 75 to 100 gallons of actual water volume. Buy one rated for roughly 1.5x to 2x your actual tank size.

Return Pump

If you're running a sump, a return pump moves water from the sump back to the display tank. The Sicce Syncra 3.0, Eheim Compact+ 5000, and the Reef Octopus DC Return Pump VARIOUS series are reliable choices. Magnetic drive pumps are the most common type; DC pumps with variable speed controllers like the Reef Octopus DC pump are more expensive but allow precise flow control and use 30 to 50% less electricity.

Live Rock

Live rock does the biological filtration in a marine tank. It harbors the nitrifying bacteria that convert ammonia to nitrite and nitrate. Budget for 1 to 1.5 pounds of live rock per gallon of display tank volume as a starting guide. Aquacultured rock from Florida or tank-raised rock is environmentally preferable to wild-collected rock. Fiji and Marshall Islands rock are wild-collected but commonly available.

Salt Mix and Refractometer

You'll need a quality salt mix and a refractometer to measure salinity accurately. Instant Ocean Sea Salt is the reliable budget option at around $55 for a 200-gallon box. Reef Crystals (also by Instant Ocean) includes elevated calcium, magnesium, and alkalinity for reef tanks. The Hanna Instruments HI-98319 refractometer is accurate and well-calibrated for seawater. Target salinity of 1.025 to 1.026 specific gravity for a reef tank.

Circulation and Flow

Coral and marine fish need strong, random water movement that mimics ocean conditions.

Wavemakers and Powerheads

Wavemakers create variable, pulsing flow patterns. The Hydor Koralia Evolution, the Tunze Turbelle Stream 6105, and the Jebao SLW-series are commonly used. For a 75-gallon reef tank, you want total circulation of roughly 30 to 50 times the tank volume per hour from all sources combined. Two Jebao SLW-20 powerheads (each rated at 528 GPH at medium settings) cover a 75-gallon tank adequately.

Closed Loop vs. Powerhead

Powerheads mounted inside the tank are the most common approach for home tanks. Closed loop systems run water through external plumbing to eliminate powerheads inside the display, but the complexity and cost mean they're mostly found on custom high-end builds.

Lighting for Marine Tanks

Lighting requirements depend entirely on what you're keeping.

Fish-Only with Live Rock (FOWLR)

Any full-spectrum LED light that provides 8 to 10 hours of illumination works. The Current USA Orbit Marine, the Kessil A80, or even a standard aquarium LED strip with marine spectrum LEDs covers the needs. Cost is $40 to $150 depending on tank size.

Soft Coral and LPS Reef

Soft corals like Zoanthids, Mushrooms, and Leathers, plus Large Polyp Stony (LPS) corals like Hammer Coral and Frogspawn, need moderate to medium-high light. The AI Prime 16HD, the Kessil A160WE Tuna Blue, and the Radion XR15w G6 are proven performers. Budget $150 to $350 per light depending on model and coverage area.

SPS Reef

Small Polyp Stony corals like Acropora and Montipora need intense light with high PAR (Photosynthetically Active Radiation) readings. The Radion XR30 G6 Blue, Kessil A360X, and the Orphek Atlantik V4 are top-tier options at $400 to $800+ per unit. SPS tanks usually require two lights over a standard 4-foot display.

For a full review of aquarium equipment across all categories, the Best Aquarium Equipment guide covers both freshwater and marine options.

Water Testing and Chemistry Supplies

Marine tanks require more monitoring than freshwater. Coral, especially SPS, consumes calcium, alkalinity, and magnesium from the water and requires supplementation.

Test Kits and Digital Meters

Salinity: Refractometer (required, $15 to $30)
pH: Calibrated digital pH meter or continuous monitor like the Neptune Systems FMM with pH probe
Alkalinity/dKH: Salifert Carbonate/KH Profi-Test or the Red Sea Reef Foundation test kit
Calcium: Salifert Calcium Profi-Test or Hanna Instruments HI-758 Checker
Ammonia/Nitrite/Nitrate: API Saltwater Master Test Kit for initial cycling; Red Sea Pro test kits for ongoing monitoring

Dosing Systems

As corals grow, they consume calcium and alkalinity faster than regular water changes replenish them. Two-part dosing (a calcium solution and an alkalinity solution dosed separately) is the most common approach for tanks under 200 gallons. BRS Two-Part Calcium and Alkalinity Concentrate is the most cost-effective option. The Neptune Systems DOS and the Kamoer X2S are popular automatic dosing pumps.

Consumables and Ongoing Supplies

These are the items you'll spend money on continuously.

Salt mix: Budget $25 to $60 per month depending on water change volume
RO/DI water or tap water with conditioner: Seachem Marine Buffer and Marine Trace for tap water; a 4-stage RODI unit like the BRS 75 GPD system for $150 to $200 upfront eliminates ongoing conditioner cost
Carbon: Seachem Matrix Carbon or Two Little Fishies HydroCarbon for chemical filtration, replaced monthly
Food: Reef-Roids, Oyster Feast, and similar coral foods; frozen Mysis shrimp and brine shrimp for fish
Coral dip: Revive Coral Cleaner or CoralRx for quarantining new coral additions

For a comprehensive list of top-rated marine equipment options, see the Top Aquarium Equipment guide.

FAQ

What is the minimum equipment needed to start a marine fish-only tank? The minimum workable setup for a FOWLR tank includes: a tank with sump or large hang-on-back filtration, a protein skimmer, live rock, a heater, a powerhead for circulation, basic LED lighting, a refractometer, and a quality salt mix. Budget $300 to $600 for equipment on a 30 to 55-gallon tank, not counting the tank itself.

Do I need a sump for a marine tank? No, but it helps significantly. A sump adds water volume (which stabilizes chemistry), provides a place to hide equipment, and allows a larger protein skimmer than a hang-on-back unit. Many successful small marine tanks run on hang-on-back filters and hang-on protein skimmers without a sump. As tank size increases past 40 gallons, a sump becomes increasingly practical.

How often do I need to do water changes in a marine tank? For a fish-only tank with moderate stocking, 10 to 15% every two weeks is typical. For a reef tank with corals, many hobbyists do 10% weekly to replenish trace elements and keep nitrate low. The exact schedule depends on your feeding rate, stocking density, and whether you're supplementing calcium and alkalinity separately.

What is the most expensive part of setting up a marine tank? Lighting is typically the biggest single equipment expense for reef tanks, especially if you want to keep SPS coral. High-end LED fixtures like the Radion XR30 cost $500 to $750 each. After lighting, protein skimmers and return pumps are the next significant costs. You can reduce the overall startup expense significantly by buying used equipment, which is widely available in the marine hobby.