I read alot of what Atrain had to say about autos, and have implimented many of his techniques.
In regards to watering seedlings. From memory, he starts off with 250ml, watering slowly, straight down, allowing the tap root to search the bottom, rather than spreading out up top. This method made sense to me, as the bottom of your pot has holes, allowing oxygen to the roots. Also, creating a solid anchor, if you will.
I really feel uncomfortable giving advice, being a rookie myself but, I am a decent researcher and believe this to be the best method.
Hopefully someone with more experience will correct me if I'm wrong.
I know that feeling well! One grow under my belt so far, what entitles me to say anything, ya know?
I agree with Yeatster about the root technique, i followed atrains method.
this time your on the right track. keep it up
I'll third that.
We had our Crown Royale in a solo cup and it took 180ml to soak to runoff, we added 60ml to account for the fact that it'd dry out faster due to spreading out in the much larger pot. Thankfully it was enough that we could measure it with our scale, so our "usual" watering methods would still work.
The first two were soaked through with a full 6 liters (in a 5 gallon fabric pot) at 15 days, which was too soon. It then took too long to dry out so by the time we wanted to start giving them nutes they still needed 3 or 4 days to finish off the last drink.
On the Dark Devil I gave her increasing watering when she'd get back to the original weight of the pot, only hitting 2 liters at 15 days, then soaked her with light nutes closer to three weeks old. I was happiest with that schedule.