I think the problem may be that the camera can't focus very on close up items. The box lids look pretty crisp, as do some of the more distant figures in the background of some of the shots.
Try taking the photos from a bit further away. Don't use optical zoom. But then crop the photo to just show the tank. While 3MP is pretty low, it should be fine for taking a photo for the web, which will generally only be 1MP at most.
Is the idea to have the shcurzen (sp?) left green, to look like replacement parts?