SPS vs LPS Coral Care Requirements

Table of Contents

• SPS vs LPS Coral: Core Differences Explained
• Coral Lighting PAR Requirements for Both Types
• Water Flow and Movement: SPS and LPS Needs
• Reef Tank Water Chemistry Parameters
• Feeding, Nutrition, and Nutrient Export
• Best Beginner Corals for Saltwater Tanks
• Compatibility, Allelopathy, and Long-Term Maintenance
• Frequently Asked Questions

Last Updated: September 20, 2026

SPS vs LPS Coral: Core Differences Explained

Small polyp stony corals and large polyp stony corals represent two fundamentally different approaches to reef building. Understanding the distinction between sps vs lps coral care requirements is essential before you commit to either type, because their needs diverge dramatically once they're in your tank.

SPS corals, Acropora, Montipora, Stylophora, have tiny polyps that retract into a dense skeleton. They're the crown jewels of reef keeping. LPS corals, Goniopora, Acanthophyllia, Euphyllia, have large, fleshy polyps that extend outward. Both are stony corals that calcify and build skeletal density, but they demand different water parameters, flow patterns, and lighting intensities to thrive.

At Blue Earth Corals and Aquariums, the most common mistake hobbyists make is treating them as interchangeable. They're not. An SPS coral that's thriving in one tank can crash in another because alkalinity drifted by 0.3 dKH. An LPS coral in the same tank wouldn't even notice. This difference alone explains why many reef keepers eventually specialize in one or the other.

The real divide comes down to three factors: calcification rate, photosynthetic dependency, and water chemistry tolerance. SPS corals calcify faster and depend heavily on zooxanthellae, the symbiotic algae inside their tissue, for energy. They're photosynthetically active organisms that need intense light and stable nutrients. LPS corals calcify more slowly, rely less on light, and can survive on a combination of photosynthesis and heterotrophic feeding. This is why an LPS coral can sit in moderate light and still thrive, while an SPS coral in the same spot will bleach.

Coral Lighting PAR Requirements for Both Types

Light intensity in reef tanks is measured in photosynthetically active radiation, or PAR. This metric tells you how much usable light energy is reaching your coral. It's the single most important factor separating thriving corals from slowly declining ones.

SPS corals need intense light, typically 250-400 PAR at the coral's location. Acropora, the flagship SPS genus, demands the high end of that range. Without it, polyps retract, colors fade, and the coral enters slow decline. The reason is simple: SPS corals evolved in shallow reef environments where light is abundant. Their zooxanthellae are adapted to high-intensity conditions. Underwater, that means 250+ PAR minimum for most species.

LPS corals thrive on far less. Most species do well at 100-200 PAR. Goniopora and Acanthophyllia can even survive at 75-150 PAR, though they'll color up better with more light. This tolerance is one reason LPS corals suit beginners, you don't need an expensive LED fixture to keep them healthy.

Here's what most guides miss: PAR drops dramatically with depth and distance from your light source. A fixture that delivers 400 PAR at the surface might only deliver 200 PAR 12 inches down. If you're placing SPS corals on a lower shelf, measure the actual PAR at that location, not at the light source. Blue Earth Corals and Aquariums recommends using a PAR meter, they pay for themselves by preventing dead corals.

The lighting spectrum also matters. Both SPS and LPS corals respond to blue and red wavelengths, but SPS corals show more vibrant coloration under high blue (420-450nm). If your goal is color, SPS corals reward intensity. LPS corals look good across a broader spectrum range, which is another reason they're more flexible.

Water Flow and Movement: SPS and LPS Needs

Flow is oxygen, nutrient delivery, and waste removal all in one. Get it wrong and your corals suffocate slowly in their own metabolic waste.

SPS corals demand strong, laminar flow, typically 15-30 times the tank volume per hour (15-30x turnover). An Acropora in a 100-gallon tank needs 1,500-3,000 gallons per hour of flow moving across it. This isn't random turbulence; it's directed, purposeful movement. The reason is metabolic: SPS corals have high oxygen demands and need constant fresh water moving through their branches to supply zooxanthellae and remove waste.

LPS corals need moderate flow, roughly 5-10x turnover. A Goniopora in the same 100-gallon tank does fine with 500-1,000 gph. They're less metabolically demanding and can extract what they need from gentler currents. Too much flow actually stresses LPS corals; their large polyps get beaten around and retract defensively.

The practical difference: if you're mixing SPS and LPS in one tank, you're compromising both. The powerheads needed for SPS will blast LPS polyps. The gentle flow an LPS prefers will starve SPS corals. This is why experienced reef keepers often dedicate separate systems or use strategic placement, SPS in high-flow zones, LPS in low-flow pockets.

Troubleshooting flow problems is where many hobbyists struggle. Dead spots behind rocks, laminar flow that doesn't reach the back wall, and uneven distribution are all common. If your SPS corals are losing polyp extension despite good light and chemistry, flow is usually the culprit. Rearrange your rockwork, add a second powerhead, or reposition your return line. The cost of a new powerhead is far less than replacing dead SPS corals.

Reef Tank Water Chemistry Parameters

This is where SPS and LPS diverge most sharply. Both need stable water chemistry, but SPS corals are unforgiving when parameters drift.

Sexy Corals Orange Passion Acro WYSIWYG →

Blue Earth Corals and Aquariums maintains our aquaculture tanks at these parameters:

• Salinity: 1.025-1.026
• Temperature: 78°F
• Alkalinity: 8.5 dKH
• Calcium: 440 ppm
• Magnesium: 1,350 ppm
• Nitrate: less than 10 ppm
• Phosphate: less than 0.05 ppm

SPS corals need tight alkalinity control, ideally 8.0-8.5 dKH. A swing of 0.5 dKH can trigger bleaching. Why? Because alkalinity drives calcification. When alkalinity drops, the coral's skeleton stops building. Stress follows. Calcium and magnesium support that same calcification process. Low calcium (below 380 ppm) slows growth and weakens the skeleton.

LPS corals tolerate wider swings. Alkalinity at 7.5-9.0 dKH works fine. Calcium at 350-450 ppm is acceptable. They're more resilient because they calcify slower and depend less on constant chemical perfection.

Nutrient export, the removal of nitrates and phosphates, matters more for SPS.

Temperature stability matters for both. A swing of 2-3°F is stressful; more than that triggers bleaching. Use a heater and chiller if your room temperature fluctuates seasonally.

Feeding, Nutrition, and Nutrient Export

SPS corals are photosynthetic specialists. They derive most of their energy from light and zooxanthellae. Feeding them directly is unnecessary and can actually harm them by raising nutrient levels. Your job is to provide light, stable chemistry, and clean water. The coral does the rest.

Best Beginner Corals for Saltwater Tanks

If you're new to reef keeping, LPS corals are your best entry point. They're forgiving, colorful, and rewarding without the precision demands of SPS.

Beginners: Start with Acanthophyllia or Goniopora. They're hardy, beautiful, and teach you the fundamentals without the precision demands of SPS.

Compatibility, Allelopathy, and Long-Term Maintenance

Mixing SPS and LPS corals in one tank introduces a hidden threat: allelopathy. This is chemical warfare between corals. Many corals release compounds that damage or kill neighboring corals. It's invisible until your corals start declining for no apparent reason.