Alright, so I moved the plants out to the balcony to get more sunlight. I water them with about a liter of water every second day or so (When the soil gets dry) and put in some fertilizer every one in a while. I got two of them now, one for growth (NPK746) and one for flowering (NPK68
. The plants seem to be getting better, got some new leaves on top and they got their color back, but the lower leaves still get dry and fall off. I also noticed some brown spots on one of the leaves ... I'm out of ideas here ...
The plants are now a month and a half old.