I'll be using Aptus on two of them and GreenPlanet on the other two to see the diference.
The two on the back are Baked in Paris, and the two in the front are In-Z-Air. The left side is beeing fed with GreenPlanetNutrients, and the right side with AptusPlantTech.
The Baked in Paris with GreenPlanet nutrients is all purple on the bottom, and all the other ones are starting to show some colour (: