[Benjamin]

I am assuming there is no such thing as a zero PAR value light but is there anything that comes close?
I ask because I (and I would guess many others) would like to view the tank after the normal lighting period has ended.
I know blue and red moonlights seem to be the most common option but I am wondering if there is anything else out there that could be used as brighter lighting for viewing.

 

[Raymond S.]

Personally I just add a "no light" space in the middle of my light timers cycle.The light is off for about 3 hrs during the middle of the day when I'm less likely to be in there
looking at the tank. But it comes on about 8:00A.M. and goes off about 8:00P.M.
Nothing says that "no light" part can't be longer so the viewing time goes till 10:00P.M.

 

[Hoppy]

The PAR range of wavelengths covers the visual range almost entirely, so there is no zero PAR light that your eyes can see. However plants don't respond to light much below 20 PAR units, so almost any dim light is effectively a zero PAR light, whatever the color of the light is.

 

[roadmaster]

I schedule my lighting period (currently 7 hour's) for the time I can view the tank the longest.
Plant's and fish need a period of darkness.
I personally believe that the advent of easily dimmable and programmable lighting to be a detriment at times for newcomer's to the hobby.
Once they see what 100% brightness is ,they are not easily moved back to 50 % even though the brighter lighting is major contributer to issues they may be having.

 

[Benjamin]

roadmaster, I absolutely agree with you, it's hard to keep that bright light off when viewing!

 

[Nordic]

Many plants will respond negatively to even small amounts of red light in the dark period....

 

[jeffkrol]

Prefer cyan or dim high k white......