Cremostarted grow question 5 years ago Hi guys, I grow 6 plants in hydroponics in a 4x4 grow box and they are 2-3 weeks old (about 7-8 cm tall). I use MarsHydro TS 3000 LED (450W) which have 2 seperate LED panels. Right now I run only one panel and would like to know when I should turn on the other panel. THX