you're most welcome! incase you want to know.. it's a minor clone on the pole behind the tank so as do give it an uncluttered bg and a bit of contrast.. too much would make it loose details on the bottom of the tank..
PS really is all about experimenting.. try it
I am going to Qatar in a few days and I am taking my camera with me so hopefully I will be able to get some great shots there. I will post the "good" shots.