The buildings, clouds, and reflections are great, but the black looks awfully one dimensional and cheapens the image.
idk about the fish, but thank you. texture and added is exactly what I think it needs... I'll fix it up when I have time.
Having the entire spectrum as a background only suggests a lack of thought or clarity in mood. Try and just use 2-3 colours, and stick to only using reds, blues or greens exclusively.