4ft 8 bulb T5 grow light distance

[Craig G]

I just got a new grow light for my plants. It runs 8 54 watt t5s. Roughly 20-40,000 lumens if i run half or all the bulbs. I'm trying to figure out a good height for it to not burn my plants. I have plants ranging from newly sprouted to a few weeks old. Any advice would be appreciated.

 

[oneeye]

T5s are much stronger than reg—florescent lights. I would keep the T5s at least 6 inches above the plant tops. You will still need to keep an eye on the plants. Also make sure you have a light breeze blowing over the plants to help keep them cool.

 

[Craig G]

I'm at 18 inches right now running half with a fan going for about 4 hours. I just hung it this morning so I'm not sure if that's too high or if I should just run all 8.

 

[oneeye]

I'm at 18 inches right now running half with a fan going for about 4 hours. I just hung it this morning so I'm not sure if that's too high or if I should just run all 8.

As time goes your plants will show you what they need. When the plants grow tall and leggy the light is too high. If the plants stay fat and short then the lights are too low and need to be raised. Indoor plants acclimate to growing conditions any sudden changes can stress the plant. I would lower your lights slowly until you get dialed in.