ok, the indica is just starting to flower now, only about 1.5 meters tall, but very wide and bushy, light cycle is just over 13hrs proper light, so i'm guessing that 12hours light for a plant to flower is a generalisation !? or just wrong !? or just depends on the individual plant or the strain or maybe growing conditions as well or maybe all of those things !?

Can someone tell me, do indicas flower later than sativas in general?

I'm guessing that these are both actually hybrids but leaning very heavily towards either way. I don't know the strains, just that their mothers were very potent, which was my choice for growing them.

Does it imply, if the mothers were potent, that the daughters will be too? or does it depend too much on the father? or growing conditions as well?

And the answer to my original question would be, you can't tell how long after preflowering that flowering will begin, anyone disagree with this?

Let me just say I enjoy learning all i can from all the information this forum has to offer, but i think one learns most from experience.