Ok, I'll give you my opinion. You probably might be able to take good full tank shots. They may look a bit blue depending on your light and the white balance of the camera. I know nothing about the camera so I can't help with setting them.
That being said, close ups "may" never happen. If you're looking at a DSLR, that "will" work with a macro lens. Read the stickies at the top of this forum. That should help.