watering

How much water should i be giving to each little seedlin once they been transfered for cube into soil one the roots have popped, im wondering cuz ive watered them fairly i thought yet it still only reads 2-3, the meters are brand new, i wonder if they defective or wat amount of water i shoukld add to each seedling if they are in 4" pots

anyone have any idea's?

As a rule of thumb with soil, if you push your finger into it and it comes out moist, thats fine. If its wet, its not.
If in doubt, its always best to lay off the water until your sure that its drying out and then start watering again accordingly.
Hope this helps.