LECA is incredibly versatile. I've been using it for over a year for propagation, growing plants in LECA, as soil additives, and adding drainage to potted plants, and I've had fantastic results.

The US dry gallon is used to calculate sizes.
Small = 4 cups
Medium = 8 cups
Large = 12 Cups

Please rinse and wash the LECA to remove any dust particles and ideal to soak for at least 12 to 24 hours before using.
It's best to use a catch pot and place the LECA in nursery pots, filling the water 1/3 full so that the LECA in the bottom is always wet and your plants get the water they need while enabling oxygen to reach the roots.