Should I darken the clouds?

Would it be better to have the cloud white or darken them a little bit?
https://s1208.photobucket.com/albums/cc374/hell-desrow/?action=view&current=DarkNight.jpg

Its gotta be darker...

Agreed; depending on how you layered your .psd (Assuming you used Photoshop), you could apply a grey filter onto it, making it darker. I'd think a charcoal grey or the shade of pencil lead should look about right; too dark and it doesn't become visible enough, and too bright means it stand out too much. Make sure the subject of the image is identifiable.

mmkay I darkened them. Would it also be a good idea to give the moon a better glow? I forgot I was gonna add a castle behind the mountains..

if you are going to make the moon's aura brighter, might want to increase the brightness of the moon itself as well; a brighter aura means brighter moon.

should I also give the water some light?

Just keep in mind that that even though the water's face is turbulent, it should still give a general reflection of the sky. You may need to do some rendering in that case.

Well this is where the picture is at. Any more suggestions?
https://s1208.photobucket.com/albums/cc374/hell-desrow/?action=view&current=DarkNight-1.jpg&

Darken the clouds WAYYYYYY MORE.

You should only see a silhouette of silver of the top of the clouds; the bottom should be stark gray-to-black. Burn tool the moon a little in it's craters to add deeper contrast, and epic dodge various edges on the surface of the water. your moon is really close to the water; it should be a lot brighter

Also: Use the eraser and erase a few of the stars surrounding the moon; make the stars a bit more transparent, and the sky show more around the moon. The moon's glow intercepts star-light within the sky, which is why it's rare to see stars near the moon if the star itself isn't Mars or some other close-proximity planet.

It looks good so far!