Is that the metal halide? Photos can be very deceiving about light intensity, but what jumps out at me is the bright spot on the wall just below the light. That tells me that a large fraction of your light is going nowhere near the plants, although you should have plenty of light on the other side of the room for reading your newspaper in the morning!

Yes shrubs n bulbs,

It is an MH. I've read 2 - 3 feet above seedlings. Is this correct?

As for reading the paper, if I have my sunglass's on, it's fine LOL.

Do you think I should lower my light?

Thanks in advance,

Bill

I'd just hang some mylar or white card on the sides of the reflector in the bright spots. That will send more light to the seedlings without subjecting them to excess heat, and maybe you won't need your sunglasses then! You can lower the light if the seedlings look to be stretching.

It would be useful to take a light meter reading at the level of the seedlings since it is completely impossible to judge the intensity by eye (except "its bright!!!"). You can do this approximately with a camera that has an auto setting.

Thanks shrubs n bulbs,

As suggested, I pulled out my trusty Sekonic light meter and took an incident reading. I'm getting f4 at 125 using ISO 100 setting. My rusty photography experience suggests that an exposure using ISO 100 on sunny summer day should be f16 at 125.

Should I assume that I should be trying to achieve the f16 setting at plant level?

Thanks for the suggestion. IÂll await feedback.

Bill

I'm more familiar with reflected readings, but I think your figures match what I'd expect off an 18% card. That would give you about 500 foot-candles from your reading at the plants. Too low.

You shouldn't be looking to match noon sun for 14 or 16 hours solid, but something like a fifth of that level usually works well for seedlings, around 2,000 foot-candles. That would be about f7.1 with your settings. Certainly many people grow with less than that, but you seem to have lots of light available, and even 3,000 or 4,000 foot-candles can be useful when the plants get a little older.

You might like to measure the incident readings at different distances from the light. And then try hanging some baffles at the sides of the reflector to see if that puts more light onto the plants at the same distance. Since you have a light meter you are in a great position to see what works well.

Thanks Shrubs n Bulbs,

Great input. I'll shoot for f7.1 / f8 range and increase as you suggested.

Much appreciated.

Bill