Running a reef tank with both corals and fish requires more specialized equipment than a standard freshwater or fish-only setup. The short answer to what coral fish supplies you need is: a quality protein skimmer, stable lighting, precise temperature control, a dosing system for calcium and alkalinity, a good return pump, and reliable water flow throughout the tank. Every one of those components matters, and a weak link in any category affects the health of both corals and fish.
This guide breaks down each category of coral fish supplies, explains what specifications to prioritize, and helps you avoid overspending on marketing-heavy products that don't deliver results. I've organized it by functional category so you can evaluate what you already have and identify the gaps.
Lighting for Corals and Fish
Reef lighting is one of the highest-impact purchases in a coral system. Corals contain zooxanthellae, photosynthetic algae that live in coral tissue and provide nutrients through photosynthesis. Without adequate spectrum and intensity, corals slowly bleach as the zooxanthellae population declines.
PAR Requirements by Coral Type
PAR (photosynthetically active radiation) measures usable light intensity for photosynthesis:
- Soft corals (mushrooms, leathers, xenia): 50 to 150 PAR
- LPS corals (hammers, frogspawn, Acans): 100 to 250 PAR
- SPS corals (acropora, montipora, stylophora): 200 to 400 PAR or higher
Position corals according to their PAR needs, placing SPS higher in the tank closer to the light source and soft corals on the sandbed or lower rock work where intensity is lower.
Recommended Lighting Options
For tanks under 24 inches deep, LED fixtures like the Kessil A360X and the Radion XR15 Pro G5 provide excellent spectrum control and PAR output. For wider or deeper tanks, the Hydra 26 HD or multiple Kessil units work well.
T5 fluorescent remains a reliable choice for consistent PAR and spectrum, particularly in SPS-dominant tanks. Many serious reef keepers run a hybrid setup with T5 supplementing LED to fill in spectral gaps.
Filtration: Protein Skimmers and Beyond
Protein skimming is the backbone of waste export in a reef system. A skimmer removes dissolved organic compounds before they break down into nitrate and phosphate, which directly affect coral health and color.
Sizing Your Skimmer
Skimmers are rated by tank volume, but these ratings are conservative. I recommend sizing one full rating tier above your actual tank volume. A skimmer rated for 75 gallons works well on a 50-gallon system under normal stocking.
Popular skimmer options: - Reef Octopus Classic 110 INT: Internal sump skimmer for tanks up to 75 gallons. Reliable, easy to adjust, and consistent performance. - Bubble Magus Curve 5: Good budget option for tanks up to 60 gallons. - Reef Octopus REGAL 150INT: Handles up to 150 gallons, excellent for mixed reef and SPS tanks. - Skimz Monzter SM151: Well-regarded for larger systems, particularly effective at removing fine dissolved organics.
Additional Filtration
Beyond the skimmer, most reef tanks benefit from:
Activated carbon: Removes dissolved organics and yellowing compounds. Run in a media reactor or filter sock and replace every 4 to 6 weeks.
GFO (granular ferric oxide): Removes phosphate, which fuels algae growth and suppresses coral calcification at elevated levels. Target phosphate below 0.05 ppm for SPS tanks. Run in a media reactor like the Two Little Fishies PhosBan 150.
Refugium: A separate lit chamber in the sump that grows chaeto algae, which absorbs nitrate and phosphate and provides a refuge for copepods that fish and corals eat.
Temperature Control
Corals are sensitive to temperature fluctuations. Most reef tanks target 76 to 78°F. Stable temperature within that range matters more than hitting an exact number; a 2-degree swing within 24 hours stresses corals more than a steady temperature 1 degree outside the ideal range.
For cooling, an aquarium chiller is the most reliable option, particularly in warm climates or during summer. A fan-based evaporative cooling unit works in dry climates and can reduce temperature by 3 to 5 degrees for minimal cost. For precise control, a refrigeration chiller like the JBJ Arctica 1/10 HP handles tanks up to 60 gallons. You can compare cooling options in detail at Best Aquarium Equipment.
For heating, titanium heaters with external controllers are the standard choice for reef tanks. The Inkbird IBS-TH2 external controller paired with a Finnex titanium heater gives you accurate temperature control without relying on the heater's built-in thermostat, which can fail.
Coral Chemistry: Calcium, Alkalinity, and Magnesium
Corals build calcium carbonate skeletons, which requires maintaining specific water chemistry parameters. This is what separates reef tank chemistry from freshwater or FOWLR maintenance.
Target Parameters
| Parameter | Target Range |
|---|---|
| Calcium | 380 to 450 ppm |
| Alkalinity | 8 to 10 dKH |
| Magnesium | 1250 to 1350 ppm |
| Salinity | 1.025 to 1.026 specific gravity |
| pH | 8.1 to 8.3 |
Calcium and alkalinity are consumed as corals grow and also by natural processes in the water. You must replenish them continuously.
Dosing Methods
Two-part dosing: Separate calcium and alkalinity solutions (typically BRS Bulk 2-Part or Randy's Recipe DIY mixes) dosed daily or through a dosing pump. Simple to start with and scalable.
Kalkwasser (calcium hydroxide): A powder dissolved in top-off water that provides calcium and alkalinity simultaneously while also raising pH. Works well for tanks with moderate calcification demand. A kalk stirrer or dosing system maintains saturation.
Calcium reactor: A device that dissolves calcium carbonate media using CO2, releasing calcium and alkalinity into the water in balanced proportions. Best for heavily calcifying SPS systems with high demand. High initial cost but low ongoing expense.
For most new reef keepers, starting with two-part dosing and testing weekly covers the basics while you learn the system's consumption rates.
Water Flow and Circulation
Corals need water movement for several reasons: it delivers food and oxygen, removes waste from surfaces, and prevents detritus from settling on coral tissue. Poor circulation is one of the most common causes of coral death in otherwise well-maintained tanks.
Target flow rates of 20 to 40 times the tank volume per hour from powerheads and return pump combined. A 50-gallon tank needs 1,000 to 2,000 GPH of total flow.
Powerheads like the EcoTech Vortech MP10 and MP40 produce gyre-style flow patterns that move water throughout the tank without creating dead spots. The Jebao SLW-10 and SLW-20 offer similar function at lower price points. Position powerheads to create random, turbulent flow rather than a single directed stream.
For a broader look at equipment options across these categories, the Top Aquarium Equipment guide covers top-rated products in detail.
Fish Compatible with Coral Tanks
Not all fish are reef-safe. Some species pick at corals, eat invertebrates, or dig up the sandbed in ways that disturb coral placement.
Generally reef-safe: Clownfish (all species), royal gramma, dartfish, firefish, chromis, and most wrasses from the Cirrhilabrus genus. Flasher wrasses are particularly coral-safe and add color to the tank.
Use caution: Some angelfish species (dwarf angels like the Centropyge loricula sometimes nip corals), certain blennies that nip at LPS polyps, and hawkfish that hunt ornamental shrimp.
Avoid with corals: Larger angelfish species, most butterflyfish (known coral pickers), pufferfish, and triggers.
FAQ
What's the minimum equipment for a coral reef tank? At minimum you need a protein skimmer, appropriate reef lighting (LEDs rated for coral PAR), a return pump, powerheads for circulation, a reliable heater, and a testing kit covering calcium, alkalinity, ammonia, nitrate, and phosphate. Without all of these functioning correctly, coral health will suffer.
How much do coral fish supplies cost to set up? A basic 40-gallon reef setup with mid-range equipment runs $800 to $1,500 for hardware alone. A high-end setup for a 75-gallon SPS tank easily reaches $3,000 to $5,000 in equipment. Most hobbyists scale up gradually rather than buying everything at once.
Can I keep corals in a tank without a sump? Yes, but it's more difficult. A sump provides additional water volume (which stabilizes chemistry), a hidden location for equipment, and space for filtration media. Without a sump, you're fitting all equipment inside or hanging it on the display tank, which limits filtration options. Many successful nano reef tanks run without sumps using quality hang-on equipment.
How often do I need to test water in a coral tank? Test calcium, alkalinity, and nitrate weekly when first establishing the tank. Once parameters are stable and you understand the tank's consumption rate, testing every 2 weeks is sufficient for most mixed reef systems. SPS-dominant tanks with fast-growing acropora should test more frequently as calcification demand is higher.
Where to Start
The smartest approach to coral fish supplies is building in order of priority. Start with a quality skimmer, appropriate lighting, and stable temperature control before worrying about dosing methods or advanced equipment. Get the fundamentals right, then add complexity. A tank with excellent skimming, correct lighting, and stable temperature will grow corals even with imperfect chemistry, while no amount of fancy dosing equipment saves corals in a tank with inadequate flow or the wrong spectrum of light.