Hello. For my newest grow, I upgraded my 4 bulb T8 setup, so a Hydrofarm T5 Designer 4 bulb setup, with the t8 bulbs hanging on the side of that light. Anyways, the pics can show you the setup. My question is, the height above the plants. The T8's used to be about 3 inches away, however, they did not emit very much heat. This T5 setup is about 87-90 degrees at 6-8 inches above, where I have it now. I wouldn't think it needs to be any closer, but I am just unsure and would like some input. Any help is appreciated! Thank you.
First. There's nothing in the pots. That being, turn off outside t8's... Twist the two outer bulbs so they go off.. Save power. Seedlings will grow very well with just 2 t5's on. When they get like 6 inches, or 3rd set of leaves, twist back on outer 2 t5's.. When they are about 9 inches, turn back on outer most bulbs. By that time, you can have room to blow a small fan over plants and keep it cooler at canopy level. 8 bulbs for seedlings is way over kill. As far as original question. 6 inches is fine for seedlings. When the get more mature, you still want any fluorescent light as close as you can get them. Whether they t12, t8, t5 or cfl.. And LST or scrog for best results. Have a good day.. Sent from my Nexus 5 using Grasscity Forum mobile app
Thank you! Exactly the answer I was looking for. Sent from my SAMSUNG-SGH-I337 using Grasscity Forum mobile app
For anyone who reads this, I wanted to update. I removed the T8's for now. I tried to twist the outside bulbs off, but this ballast is wired so if you twist the outside one off, the one right next to it also goes out. Instead I spread the pots apart so the tops are about an inch away from each other, and there is a nice cleared channel running down the center. I have a fan going from the cold air intake into the room, blowing down that inside channel between the pots (don't worry, pics are attached if you are confused). Anyways, I have a second fan at the other end of the pots stirring more air around. After this, at the same height of about 7 inches above the actual soil, the temps dropped from 85-87 to 75-76. Significant reduction. So I dropped the light a little bit closer and the temps are now at a perfect 78 degrees for the seedlings. Thanks again for your help!