I have a lighting problem.

I have a night time scene I am trying to make visible, but to my main monitor it looks perfectly visible on my secondary, and I’m assuming this is what most everyone else sees when they see the image, is there something I can do to ensure that it is bright enough for everyone else to see, and not too light for night time?

Yes, you need to figure out which of your monitors is too dark and which one is correct. This should really be done with a meter, but this page will at least give you a general idea: http://www.lagom.nl/lcd-test/black.php (also check the gamma test on that same site)

From your description, it sounds like one of your displays will fail this. Find out which one, fix it as a best you can, adjust your image as needed. Then decide if you want to make it overly-bright to compensate for monitors that are too dark.