Can I water this size plants with 10% por volume?

Absolutely but i wouldnt use a nutrient solution until a month of being in the dirt

So you guys usually water till It runs off and wait till dry out? My doubt was Just If I could do something like that (run 10% or till runs off and water again only when It is dry) or If those girls are to Young to receive water like that (right now I am watering pre defined small amounts every day twice a day)?

I do NOT water by measurement. There are too many variables to say give 10% per day. I go by what the plants and soil need. In small pots like that you may need to water every day but you have to check the soil to see if it needs it. With young sprouts make sure you water well beyond the plant and get the soil all the way to the bottom moist. Roots grow out seeking moisture so you don't want them to encounter dry soil.

Just make sure that soil is never dry, be careful when you water. Let them do there thing, they got to grow in those roots.

Water right though. You want runoff. Then wait till dry. Good drainage is important. You want the roots to reach for water at the bottom.