I wanted to discuss that feeling that you get when you take a picture of your aquarium. Everything looks perfect to your eye, but the camera gives you a blue picture that seems less focused, slightly rounded, and overall it seems rather meh. Nothing that makes you want to share those images with others, at least not with any sense of pride. I can complete a photo session around my tank and think the images look pretty good based on what I saw on the LCD screen on the back of my Nikon, but that's while I'm being bathed in blue light.  When I import all the images from the memory card onto my computer, I see dozens of washed out images that look like junk.

A few years ago, my friend told me to shoot all my picture in RAW, so I do.  This allows me to make all sorts of color correction in post (post processing), fixing what the data to match what the human eye sees. My camera's white balance is pretty much worthless, it turns out. I googled it years ago, after trying repeatedly to set it to handle my tank's 20000 Kelvin spectrum.  It can't do it, it doesn't even come close.  With all the data contained in every RAW image, I can change the spectrum with a slider, pulling out the blue and providing a nice clean image that is closer to reality.  Of course, if you want pure vivid colors in a blue image, that's your perogative.

In addition, I use something called Lens Correction that takes away the slight bulge of every image, making things square and straight. When I look at pictures now, I can immediately see how the lens distorted the shape of an aquarium or sump I've photographed, but Lightroom corrects this with the click of a mouse. 

I sharpened the image, try to reduce any areas that appear blown out since some areas are very bright (sand, light green corals) while others are less intense (rocks, brown corals), and crop if necessary to focus on the subject.

tl/dr version: Here's a before and after pasted together to compare side by side. Top image, notice the black trim is a little bowed upward in the middle above the Shadowcaster? It's fixed in the lower image. And the greens are far more vivid in the lower picture as well.

If you take a bunch of pictures and don't like the results, it's very likely because you need to clean them up in Photoshop or some other software. This is also the case for SCUBA photography. Those incredible pictures we see via NatGeo? Every one of them was carefully edited for maximum visual effect.