What size pots /cups do you have them in
Since your plant is only 3" it probably does not have a big root system yet
i would just water right around the plant to where the roots might be
idk how big you container is , but it takes longer for a whole pot of soil to dry out then just in the center where your roots are right now
just give enough water to ensure that the roots got some , then wait a few days when its pretty much dry and water again
roots grow better through the dryer soil then the wet
once your plant gets bigger and the roots starts to full the container then water until it comes out the drain holes
but like water a little at a time first to see if its gonna drain , you dont want to just pour a gallon of water in their just to make sure it drains
I water till it comes out the drain holes but i water a little at a time
but your plant is so small right now and has a small root system you do not need all that water
just a little every few days after it gets dry