Dialing in your reef tank parameters can feel overwhelming at first, but a clear, easy-to-follow reef tank parameter chart turns guesswork into a simple routine. Whether you keep soft corals, LPS, or SPS, understanding your target ranges (and why they matter) is the key to long-term stability and healthy, vibrant corals.
Core Reef Tank Parameter Chart (Saltwater Display Tanks)
Use the chart below as a quick reference for most mixed-reef systems. Individual tanks may vary slightly, but these ranges are a safe, proven starting point.
Tip: Consistency is more important than chasing a “perfect” number. Aim for stable values within these ranges rather than constant adjustments.
- Temperature: 77–79°F (25–26°C)
- Specific Gravity / Salinity: 1.025–1.026 (34–35 ppt)
- pH: 8.0–8.4 (minimal daily swing)
- Alkalinity (dKH): 8–9.5 dKH
- Calcium: 400–450 ppm
- Magnesium: 1250–1400 ppm
- Ammonia (NH3/NH4): 0 ppm (always)
- Nitrite (NO2): 0 ppm (mature tank)
- Nitrate (NO3): 5–15 ppm for mixed reef; 2–10 ppm for SPS-focused systems
- Phosphate (PO4): 0.03–0.10 ppm (avoid 0.00)
If you are still cycling your tank, check out our guide on how to cycle a saltwater aquarium before trying to lock in these reef parameters.
How to Use This Reef Parameter Chart in Daily Practice
Knowing the numbers is only half the battle. The real magic happens when you build a simple routine around them.
1. Create a Testing Schedule
- Weekly: Test alkalinity, calcium, magnesium, nitrate, and phosphate.
- Twice per week (or more): Check temperature and salinity, especially if you do frequent water changes.
- Monthly: Confirm pH, double-check salinity calibration, and compare test kits if something seems off.
Record your results in a simple logbook or spreadsheet. Over time, you will see patterns in consumption and can fine-tune dosing instead of reacting to surprises.
2. Make Small, Gradual Adjustments
- Alkalinity: Adjust no more than 0.5–1.0 dKH per day using a reef-safe buffer or dosing system.
- Calcium & Magnesium: Raise these slowly over several days to avoid shocking corals.
- Nutrients (Nitrate & Phosphate): If they are too high, increase export with water changes, better skimming, or refugium growth. If too low, feed a bit heavier or reduce aggressive filtration.
For more detail on dialing in nutrients, see our article on controlling nitrates and phosphates in reef tanks.
3. Match Parameters to Your Coral Mix
Different coral groups prefer slightly different conditions, though they all thrive with stability:
- Soft corals & LPS: Often do well with nitrates 10–20 ppm and phosphate 0.05–0.15 ppm.
- SPS-dominant tanks: Usually benefit from lower, but still measurable, nutrients (nitrate 2–10 ppm, phosphate 0.03–0.08 ppm) and very stable alkalinity.
Before you stock your tank, review our beginner reef coral guide to plan a coral list that matches your maintenance style and parameter goals.
Putting the Reef Tank Parameter Chart to Work
A reef tank parameter chart is more than a reference sheet—it’s your roadmap to a stable, thriving system. Post it near your aquarium, keep your test kits handy, and log your results regularly. Over time, you will learn your tank’s natural rhythm: how fast it uses alkalinity and calcium, how feeding affects nutrients, and how small changes ripple through the system.
Stay within the recommended ranges, avoid sudden swings, and resist the urge to constantly chase new numbers. When your parameters are steady and your corals are open, growing, and colorful, you will know the chart is doing its job.
Sources
- Red Sea Reef Care Program documentation (reef parameter recommendations)
- Brightwell Aquatics & Seachem reef chemistry product guides
- Randy Holmes-Farley, “Reef Aquarium Water Parameters” (archived chemistry articles for reef hobbyists)
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