Nikon P500


Reefing newb
This seems like a good place for this thread, if I'm wrong, feel free to move it.

I picked up a Nikon P500 a week or so ago and I'm having trouble getting really nice pictures with it. Does anyone else have this camera or a similar super-zoom? If so, what settings do you find work best? My 20g is a marineland kit and has a small led set that came with it. I see so many people taking stunning pics under blue lights, but it seems like no matter what I do they either come out completely dark or there isn't any color at all. If I use the flash then I lose the blue light effect completely. I have the camera on a tripod and use a 2 sec delay so there isn't any shake from pressing the button. My best results are with a 4.6-5 aperture, ISO 400-800, 1/2 sec shutter speed.
I dont have this camera exactly, but many of us edit our photos afterwards and reduce how blue it is. I use iPhoto, but you can do it with many other photo editing software.

There might be a trick to taking the photo with less blue, but im not aware of it.
GIMP is an open source photo editing program, can do a lot of what Photoshop can do but it's user interface is a bit of a clusterfrack.