I've seen posts that a period of darkness within the overall photoperiod is not known to enhance plant growth.

But my question comes from the other direction - is there any basis to think a period of darkness is *not* desirable? (algae, plant growth, fish, etc.)

Goal is simple. I recently delayed light onset at beginning of day in order to shorten overall photoperiod (which is currently from 11am-8pm). But now lights are out before I go to work, and I enjoy my morning coffee looking at tank.

I would like to:
Lights ON 6-8am
Lights OFF 8am-1pm
Light ON 1pm-8pm

Curious of anyone does this, or has suggestions/cautions. Duration of first ON phase not relevant, as long as lights come on when I do


Thanks,
growitnow

Some have done this for this same reason.
I really do not think it's that critical, as long as you do not turn them on for only 1-3 hours, instead going for a 5-6 hiur frame and not leave the midday period too long, not more than about 2 hours or so.

I just turn the lights on late in the day so I can see things at night when I have more time.

Regards,

Tom Barr

Tom, thanks.

Not having a long dark period in the middle makes sense upon your reply. Particularly if one is driving CO2, where dark+CO2 = high CO2 levels plus some wasted gas.