You should learn to water by weight. Do not water by a schedule. And water sufficiently when you do so as to wet all the medium. Volume used is mostly dependent on size of container.
I have them in 100l pots at the moment how would hi work out the weight of the each plant
Get yourself a moisture meter,about 30$ will help you get a feel for it.
Pick the container up when it’s dry. Water until a little runs out the bottom. Pick it up again. Then pick it up daily. You’ll quickly get used to picking it up and immediately knowing if it’s dry enough to feed again.
I learned this about halfway through my first grow and has helped me tremendously ever since. Water seldom but water well. It's not good to water a little bit constantly. Wait for the container to be light and then give it a good water. I tend to water in circles from the center out. Watering the edges helps guide the plant to grow roots outward as well as down. If you use a good amount of perlite, even if you water heavy, you shouldn't have an issue as it will drain. Cannabis likes a well aerated medium.
I use bamboo skewers and pierce the living hell out of the medium. Everywhere including under the plant. Don’t be afraid of hurting the roots. I do this between feeding/watering every time. The further into flower you are the bigger the blast of terps as you do it. You’ll know what your bud is going to smell like.
