Starting CBD seeds in small cups and moving them up twice lets roots fill each container before the next step, which produces sturdier plants than sowing straight into a large pot. Autoflowers are again the exception and should go into their final container immediately. The container size chart at https://calmcbdseeds.com suggests final volumes by strain height, ranging from seven litres for compact autos to over thirty for tall photoperiod plants. Root bound plants stop growing at the worst possible moment, usually just before flower.