Depends on how strong your feeding them...I've found a feed/feed/water program work awesome. And just feed lightly. Start with 1/2 tsp/gal and work your way up. Make sure you use the Gro & Bloom terra for soil. Their isn't much calcium in them, so its good to use their Ultimate thrive with it, its in their feeding schedule. Use 5ml/gal on top of the bloom terra..... I've been using the stuff for a couple of years now, and its always been really consistent, and great yields. Let me know if you got any other q's.