How Much Flow Does My Reef Tank Need?
Quick Answer
Most reef tanks need 20-50x total tank volume turnover per hour. LPS and soft corals prefer lower flow (20-30x), while SPS corals thrive with higher flow (40-50x or more).
The ideal tank size depends on your goals, budget, and experience level. Here's a breakdown to help you decide:
Minimum Size: 20-30 Gallons
While nano reefs (under 30 gallons) are possible, they're actually harder to maintain. Small water volumes mean parameters can swing quickly. A 20-gallon tank might seem easier, but it requires more frequent monitoring and water changes.
Beginner Sweet Spot: 40-75 Gallons
This range offers the best balance of stability and manageability. Benefits include:
- More stable water parameters
- Room for a diverse fish community
- Space for corals to grow without crowding
- Forgiving of beginner mistakes
- Equipment is readily available and affordable
Ideal Range: 75-150 Gallons
If space and budget allow, this range is optimal. You'll have:
- Excellent parameter stability
- More fish and coral options
- Better aquascaping possibilities
- Room for a proper sump and equipment
Key Considerations
- Floor support: Water weighs 8.3 lbs/gallon. A 75-gallon tank with rock and equipment can weigh 800+ lbs
- Electrical: Reef tanks need multiple outlets for equipment
- Water source: You'll need RO/DI water for top-offs and water changes
- Budget: Larger tanks cost more upfront but often save money long-term on livestock losses
Bottom Line
Start with the largest tank you can afford and accommodate. A 55-75 gallon tank is the sweet spot for most beginners—stable enough to learn on, but not overwhelming to maintain.
Ready to stock your tank? Browse the ReefBay marketplace for corals and fish from verified sellers. Track your tank parameters with the ReefBay app to stay on top of your reef's health.
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