A bad weed never dies

Hola! I noticed that the two plants (the older OS and the younger WG) were not growing as much as their sisters due to (most likely) some lack of light, so I decided to buy a second FECIDA LED earlier this week. It seems, at least for now, that it's positively affecting their growth. Also, we had very bad weather this week, and some algae started growing on the soil due to the high humidity -- after removing the algae to avoid spreading, I shut down the hydro system for a couple of days to make the soil dry properly. On the bright side, you can see the younger OS almost ready to be cut down: I believe that in one week or two she will reach her full potential, accordingly to the initial schedule.