Can too much light slow down growth?

[DexterC]

Hello growers!

Recently I changed my lights to some LED bulbs that draw 12 watts each (70-80 watts equivalent) at 6500K and I run 2 of them for a single plant together with natural sunlight since the room I am growing is really bright during the day. The bulbs don't put out any significant heat plus I got really good air flow, the room is a nice 26-28 °C or 78-80 °F, sometimes lower, so I am not worried about heat issues. What I was curious about is if I move the lights to close, could this slow down growth, knowing that the sun already provides a lot of light?

I chose to not go with a grow tent and fully artificial grow since she could be grown outdoors in very good conditions, but I prefer to take a bit more control over it and ended up sort of blending the environment, also I would like to know if this is a good idea, to bring artificial help while giving her a bit of mother nature as well.

These might be stupid questions but I prefer to get clarity over this, if too much light is too much for the small plant and if blending environments can bring benefits overall.

 

[TorturedSoul]

I doubt you're in danger of providing too much light. First, unless it's a glass house or one that somehow rotates to keep your window in line with the sunlight, you're probably only getting "direct sunlight" for a relatively small portion of the day. But assume that you DO have a magical spinning house, and the windows are pointed at the sun for 18 hours per day during the growth phase (12 hours per day during the flowering phase). Are the windows open during all of those hours? If yes, you probably have screens in them - which do block some light (actual amount will vary somewhat, depending on the specific "model" of screen). If no, the windows might still have screens installed (see previous), plus a pane of window glass will block at least 9% of the light. And if the windows were installed relatively recently - within the last 45 years or so - they're probably double-pane windows, meaning that the second pane will block 9% of the light that the first pane allowed to reach it. (Some newer windows are triple-pane ones.) If you're not cleaning both sides of the window on a weekly basis, well...

A couple of little 12-watt residential LED light bulbs will be fine. You might want to pull/pry/cut the half-globe plastic cover off of the business end so that more of the light they produce will actually reach your plant.

Light doesn't actually have to be all that bright for our Mark I Eyeballs, Human (and brain) to perceive it as being really bright. If those bulbs are placed at the minimum distance at which they can illuminate the entire plant instead of two spots on it, they're not likely to be too close. Especially when you are trying to grow a plant in an open area (room) instead of a small space (tent/box/closet) - because a lot of that light will fall on something other than your plant and, therefore, be wasted.

If a person doesn't know the answer to a question, and asks it in order to change this... it's not really a stupid question, IMHO.