Another one I just ran across in another thread that I don't know if it's been said:
"The plants need darkness. 24/0 is a bad light cycle and will hurt growth/yield.".
Well, considering I veg in 24/0 and have for eight years where on average I get about a 1/2 lb per plant, I'd have to say we've got another broscience statement.
this is a difficult one, because both sides have good arguments... multifold...
e.g. IF lights are too strong, and plants are capped on CO2, then alot of photosynthesis doesn't happen with CO2 but O2 instead resulting in a toxic buildup - which is cleared in the darkbreath at night by "rubisco"...
also, plants actually count the number of day-hours, store energy for that, and then still grow during the night... there's actually some evidence out there that show root development is better if you give a night....
but actually all these processes can happen as well during the day, at a somewhat reduced strength... and for HID lamp users, an "always-on" mode is really best! preventing lightloss from bulb degradation... can also use a less stong lamp then or light out a greater areal with it...
then it seems some plants grow even more healthy under 24h lights as 18/6...
undecisive