Thanks for reminding @Rgaaana , let me edit. It’s %60-75 since the beginning. 
This was a one time over watering and all others received the same amount. Maybe it’s not even much water, I beleive so cuz there are no holes. I never water daily, always let them dry and weight the pots to make sure.
I suspect if the inner surface of the pots ( paper pots , not plastic) might have been an effect. 