Attempt an aquarium calculator to determine just how much substrate, gravel, or sand you require

https://fish-tank-size-calculatorattq775.theglensecret.com/10-things-you-learned-in-kindergarden-they-ll-help-you-understand-tank-stocking-calculator

Try an aquarium calculator to find out how much substrate, gravel, or sand you require. Get handy estimates based on depth and tank measurements.