Setting up a reef tank requires a different set of supplies than a standard freshwater or even fish-only saltwater aquarium. At a minimum, you need a saltwater-rated filtration system, a protein skimmer, live rock or ceramic biological media, a quality lighting system that outputs the right spectrum for coral photosynthesis, a heater, a wavemaker or powerhead for water movement, and a way to test and maintain water chemistry. That's the core list. Everything else builds from there depending on the type of corals you want to keep.

This guide walks through each category of reef tank supplies in practical detail, covering what function each serves, what to look for, and specific product examples.

The Foundation: Tank and Sump

Most reef keepers use a sump-based system rather than hang-on-back filters. A sump is a secondary tank (usually located in the cabinet beneath the display tank) that handles filtration equipment, increases total water volume, and keeps equipment out of the display.

The display tank connects to the sump via an overflow box or built-in overflow. Water drains by gravity into the sump, passes through filter media sections, and a return pump sends it back to the display tank.

For beginners, a 40-breeder or 60-gallon tank with a simple 20-gallon sump is a manageable starting size. Smaller reef tanks (under 30 gallons) are harder to maintain stable water chemistry in because small water volumes swing more dramatically.

Overflow Options

Reef-ready tanks come drilled with built-in overflows (like the Red Sea Reefer series). Non-drilled tanks can use a hang-on-back overflow box (CPR CS50 or Eshopps Overflow Box are common choices). Drilled overflows are more reliable; siphon-based HOB overflows risk losing siphon and flooding the sump or tank room floor.

Protein Skimmer: The Reef Essential

A protein skimmer removes dissolved organic compounds from water before they break down into ammonia and nitrate. It works by creating fine bubbles that organic molecules adhere to, concentrating them in a collection cup that you empty periodically.

For reef tanks, a protein skimmer is not optional. Corals are sensitive to dissolved organics and nitrogen compound accumulation. Skimmers extend the time between water changes and help maintain the low nutrient levels SPS and LPS corals need.

Sizing by tank volume plus sump:

  • Up to 50 gallons total water volume: Bubble Magus Curve 5, Reef Octopus Classic 100HOB
  • 50-100 gallons: Aqua Maxx HOB-1.5, Reef Octopus Classic 110SSS
  • 100-200 gallons: Bubble Magus Curve 7, Reef Octopus Regal 150SSS

The Reef Octopus Regal series is widely regarded as the best build-quality-per-dollar option in mid-range skimmers. The Bubble Magus Curve series is priced lower and performs well for the price, making it a good starting point.

Lighting: The Most Species-Specific Decision

Coral photosynthesis requires light in the blue spectrum (420-450nm) and white/full-spectrum light at sufficient intensity. Different coral types have different lighting requirements:

Soft corals (mushrooms, zoanthids, leather corals): Low to medium light. Approximately 50-100 PAR at the coral's position.

LPS corals (brain corals, hammer coral, torch coral, frogspawn): Medium light. 75-150 PAR depending on species.

SPS corals (acropora, montipora, stylophora): High light. 150-300+ PAR at coral placement.

Specific LED fixtures:

  • Kessil A160WE Tuna Blue: A solid option for tanks up to 24" wide. Good spread, high-efficiency LEDs, includes a controller port.
  • AI Hydra 26 HD: One of the most popular mid-range reef LEDs. Programmable RGBWAB channels, mobile app control, covers approximately a 24x24" footprint effectively.
  • Radion XR15 Pro by EcoTech Marine: Premium option with excellent spectrum control and proven coral growth results. Pairs with the EcoTech ReefLink for app control.
  • Kessil AP9X: High-output option for deeper tanks or SPS-dominated displays.

For a budget-focused build, the AI Prime HD covers smaller tanks (24" wide or under) at a lower price point than the Hydra.

Wavemakers and Powerheads

Corals need consistent water flow to deliver nutrients, remove waste, and prevent detritus from settling on coral tissue. Most reef tanks use at least two powerheads positioned to create random, intersecting flow patterns that simulate ocean surge.

EcoTech Marine MP10: The benchmark powerhead for small-mid reef tanks. Wireless control, programmable flow modes, extremely quiet. Expensive but reliable over years of use.

Jebao SW-4 or SW-8: Budget-friendly alternative. Significantly lower price than EcoTech. Works adequately in most reef setups without the advanced programming features.

Tunze Turbelle nanoStream 6020: A strong mid-range option with adjustable magnetic mount, steady flow, and quiet operation. Popular in European reef keeping.

A general rule: combined turnover from wavemakers should be 20-40x tank volume per hour for a mixed reef. A 60-gallon display tank wants 1,200-2,400 GPH of total flow circulation.

Water Testing and Chemistry Maintenance

Reef water chemistry involves more parameters than freshwater. The critical ones:

  • Salinity: 1.025-1.026 specific gravity (or 35 ppt) for most reef tanks
  • Temperature: 76-78°F for most corals
  • Alkalinity (dKH): 8-10 dKH for mixed reefs, 9-11 for SPS
  • Calcium: 400-450 ppm
  • Magnesium: 1,250-1,350 ppm
  • Ammonia, nitrite, nitrate, phosphate: As low as possible, especially in SPS tanks

For testing, the Salifert test kits are widely trusted for accuracy. The Red Sea Coral Pro and Hanna Instruments ULR Phosphorus Checker are commonly used for precision phosphate testing.

For maintaining alkalinity and calcium in tanks with significant coral growth, two-part dosing systems (BRS Two-Part is a popular and affordable option) or calcium reactors are the standard approaches.

For UV sterilization in reef setups, our best UV sterilizer for reef tank guide covers how to balance sterilization with preserving beneficial microplankton. And for water purification, our best RODI unit for reef tank guide covers making pure top-off and saltwater mixing water.

Heaters and Temperature Control

Saltwater is more temperature-sensitive than freshwater. Sudden drops or spikes above 82°F can cause coral bleaching. Use a heater sized at 3-5 watts per gallon of total water volume, and run it in the sump rather than the display for cleaner aesthetics and easier replacement.

The Eheim Jager and Cobalt Aquatics Neo-Therm are the two most consistently recommended reef heaters. Both have accurate thermostats and break-safe designs. The Inkbird IBS-TH2 or Inkbird ITC-308 temperature controller can serve as a backup shutoff if the heater's thermostat fails, which is how most heater accidents happen.

RODI Water System

Reef tanks require purified water for top-off (replacing evaporation) and for mixing new saltwater. Tap water contains chloramine, nitrate, phosphate, silica, and other compounds that fuel nuisance algae and stress corals. A reverse osmosis/deionization (RODI) unit removes 99%+ of dissolved solids, producing water suitable for the demanding chemistry a reef tank requires.

The BRS 4-Stage Deluxe RODI is a standard starting point for hobbyists. The 5-stage version adds a second DI stage for lower TDS output, which matters if your source water has high mineral content.

FAQ

How much does it cost to set up a reef tank? A minimal but functional 40-55 gallon reef setup runs $600-1,000 for equipment: tank, sump, skimmer, basic LED lighting, wavemakers, heater, RODI unit, and initial livestock. A high-end build with premium LEDs, EcoTech wavemakers, and a calcium reactor can run $3,000-5,000 or more for the same tank size.

Can I keep reef corals without a sump? Yes, but it's harder. All-in-one reef tanks like the Red Sea MAX Nano or Innovative Marine Nuvo tanks have built-in rear filter chambers that handle equipment without a separate sump. These work well for smaller mixed reef setups at the cost of less flexibility and smaller total water volume.

What are the easiest corals for a beginner reef tank? Mushroom corals (Discosoma), zoanthids (zoanthus and palythoa), green star polyps, and pulsing xenia are the most forgiving. They tolerate lower light, variable water chemistry, and less frequent maintenance while still looking impressive in a display.

Do I need a UV sterilizer for a reef tank? Not mandatory, but useful. A UV sterilizer reduces pathogen load and can help prevent disease outbreaks in fish, but it also reduces populations of beneficial microplankton. Many reef keepers run a UV sterilizer intermittently rather than continuously.

Getting Started

The supplies that matter most in order of priority are: water quality (RODI and salt), stable chemistry (testing and dosing), appropriate lighting for your coral type, and enough flow. These four areas drive the health of the reef more than any other equipment decisions. Build the foundation right before spending money on premium lighting or advanced equipment.