Ventilation intake

Indoor Growing Climate
21

Not necessarily. I tape up my led indicators on a plug strip. Im aware of the study and did in anyway. 5 sec of work to eliminate a risk is not a waste. Using duct with a bend in it for the passive airflow to eliminate light is also not a waste. Just being smart. There is a difference.

22

We also forget to mention one of the unhappy consequences that can happen: seeds or emaphrodite. Few growers have said they got seeds from a tiny amount of light

23

Bugbee mentions LED indicator lights as an example of sources that are too dim to matter (and perhaps that’s what @Poseidon1 was referring to). Light spill through an inlet could be different, and Bugbee describes an easy way to tell.

To my way of thinking, ignoring science and doing useless things in hope of better results is superstitious. But Bugbee’s findings indicate it does no harm in this case, so if some people feel better fixing non-problems, I’ve no objection – so long as they don’t claim it’s necessary.

I’ve seen anecdotal reports that excessive light at night during flowering can cause hermaphroditism, which will produce seeds if those plants aren’t yanked promptly. I haven’t found evidence of this, though, and ILGM’s two guides on the subject don’t mention it:

Hermaphroditism in Marijuana – What causes plants to go hermaphroditic?

How to Identify, Prevent, and Deal With Hermaphrodites in Your Cannabis Grow

So, the effect may be genuine, but like so many things involving cannabis, we don’t know for sure or what the threshold is. (Or maybe my internet search was inadequate.)

24

I am finding tons of stuff with this search:
.
“do cannabis plants really need total darkness when lights are off? in nature they have the moonligh”

Also remember to use A.I.

25

I get lots of hits with that search phrase too, but only one that addresses the question (near the end of the article), and it cites Bugbee’s research:

Growing cannabis: Debunking the light leak myth .

The others address how long the dark period should be during veg and/or flowering and whether it’s helpful to start flowering with an X-hour dark period, where X is either 24, 48, or 72.

If I’ve missed one that’s relevant, please provide the link.