Home / Guides
Aquarium guides
Clear, worked explanations of the numbers behind a healthy aquarium — each one paired with a calculator.
- How to calculate aquarium volume (every tank shape)Formulas and worked examples for rectangular, bow-front, cylinder and hexagon fish tanks, in US gallons and liters, plus how to find the real water volume.
- How much does a fish tank weigh?Empty, filled and set-up weights for standard fish tanks from 5 to 150 gallons, how each part adds up, and what a heavy aquarium means for your floor.
- How much substrate do I need?How to calculate aquarium gravel, sand and aqua soil by weight or volume, how deep to make the bed for fish, plants and reefs, and a chart for every tank size.
- Aquarium heater size guide: how many watts per gallon?Choose the right aquarium heater wattage from tank size and room temperature, when to use two heaters, where to place them, and what heating costs per month.
- Aquarium filter flow rate: GPH and turnover explainedHow many gallons per hour your aquarium filter should move, turnover targets for every tank type, why rated flow overstates real flow, and when flow is too strong.
- Aquarium water changes: how much and how often?How much water to change and how often, the maths of nitrate dilution, where a weekly routine settles, and a safe step-by-step method for any tank.