It's a 400w metal halide lamp, my babies are about 21 days since sprouted out of soil. What you guys reckon? Thanks in advance
If your plant gets to hot the upper leaf's will fold up like a envelope and the tips will curl up to. 2 to 3 feet
Depends, do you have a cool tube? Heat burns the plant before lumens, i have a cool tube 1000 watt and kept the light 2 feet from the tops, so you should be fine at that range with your wattage, if you dont have cool tube i suggest doing the back of the hand test.
I would recommend getting a couple cfls and vegging under them until the plant gets larger. Then it will be better able to fight heat and light stress from the MH. Cfls make nice tight nodes too. A light bulb socket, two way splitter and two pack of cfls should cost less than $15
I currently have the light 16 inches from the tops. My plants are about 10 inches and I've not got a cool tube. I had them 22 inches away and I thought that would be far too much. My temps are 86-87f which I know wouldn't be a problem as its been up to 95f lately with the weather being hot recently outside
I can't see that picture on my phone but I guess its the chart and I can't imagine my plants would thank me if they were 5 inches away