Definitely was late with defoliation. I trimmed one more then the other, mainly because I want to observe the difference in between both. It seems as if the untrimmed plant has grown more, as the baby buds seem a bit thicker. However, the non-defoliated plant seemed to lack in nutrients which it started leeching of its own big fan leaves, which were fallen off. I've removed those.
This time plants both got about 1.5 liter of water each, which seemed to be ok for at least 3 days. Next feeding will be only water again, ph corrected to ~5.6