1. What is Fish Tank Water Capacity?

Fish tank water capacity refers to the actual volume of water available in an aquarium after accounting for displacement caused by substrate, decorations, rocks, and other tank contents. This is the true water volume that fish and aquatic life inhabit.

2. How Does the Calculator Work?

The calculator uses the capacity formula:

Where:

• \( Volume \) — Total tank volume in liters
• \( Displacement \) — Volume displaced by substrate and decorations in liters
• \( Capacity \) — Net water volume available for aquatic life

Explanation: The calculation accounts for the space occupied by gravel, sand, rocks, driftwood, and other aquarium decorations that reduce the actual water volume.

3. Importance of Accurate Capacity Calculation

Details: Knowing the true water capacity is essential for proper stocking levels, medication dosing, water parameter calculations, and filtration system sizing. Overestimating capacity can lead to overstocking and water quality issues.

4. Using the Calculator

Tips: Enter the total tank volume in liters and the estimated displacement caused by substrate and decorations. For substrate displacement, a general rule is 1-2 liters per 2.5 cm depth for standard gravel.

5. Frequently Asked Questions (FAQ)

Q1: How do I estimate substrate displacement?
A: For gravel, estimate 1.5-2 liters per 2.5 cm depth per 30 cm² area. Sand typically displaces slightly less volume than gravel.

Q2: Why is net capacity important for fish keeping?
A: Fish stocking guidelines are based on actual water volume. Overestimating capacity can stress fish and compromise water quality.

Q3: How much do decorations typically displace?
A: Large rocks and driftwood can displace 1-5 liters each. Measure by water displacement method or estimate based on size.

Q4: Should I include filter volume in calculations?
A: No, filter volume is separate. This calculator focuses on the main tank water capacity only.

Q5: How accurate are manufacturer's volume specifications?
A: Manufacturer volumes are typically total volume to brim. Actual water capacity is usually 10-20% less due to displacement and recommended fill levels.