I have a 400 watt mh light with 4 plants. Today makes 3 weeks. I have a few leaves turning yellow on the ends and drying up. I haven't given them any nutes yet, I planted in happy frog potting mix, I'm just wondering if my light is too close maybe? I have it 12 inches above my plants. I'll share some pics if I can
I don't have a light meter, I'm just getting started with the indoor stuff. Some of the stuff I read online said no further than 12 inches away with the light. At that distance to me, it looks like 4 plants in 3 gal cloth pots, is too much for the area. I have a thermometer on the wall in my room, but not close to the plants. It stays a steady 70 degrees in the room. I boxed in a 4' x4' area and lined it with foil to maximize light exposure, but I have been worried the whole time about the heat. I do have a 6" forced ventilation system also. With a fan pointed right on the plants.
I don't have a light meter, I'm just getting started with the indoor stuff. Some of the stuff I read online said no further than 12 inches away with the light. At that distance to me, it looks like 4 plants in 3 gal cloth pots, is too much for the area. I have a thermometer on the wall in my room, but not close to the plants. It stays a steady 70 degrees in the room. I boxed in a 4' x4' area and lined it with foil to maximize light exposure, but I have been worried the whole time about the heat. I do have a 6" forced ventilation system also. With a fan pointed right on the plants.
You can download a light meter app to your smartphone. It will give you a good idea where you are light intensity wise.
You want the fan oscillating across the bottom of the canopy. Not a constant directed air flow right in to the plants. Think wind burn with it pointed directly at plants on a constant basis.