how much water pre feeding around 3 weeks

so how much water are u guys feeding ur plants when there around 3 weeks old per watering. and around how long till the next time u water?

I start off small with the seedlings, they don't need much water. As the plant progresses, so does the watering, until i reach the point of getting a bit of drainage from the pots. From then on, I don't water em again til u can pick up the pot and it feels empy. U get a feel for it real easy, just pick up the pots after u've watered em and 'feel' the weight.... wait a few days and pick it up, u can tell if there's still moisture down there by the weight.

i only water mine when the soil is dry, every 2-3 days.