Re: Painting the back of your tank
#2
I used black vinyl wrap (sold by car places on ebay) to cover the back of mine, you make it stick by spraying a mixture of water & washing up liquid onto it and then stick it to the back of the tank - you can then move it around, you'll also need to get rid of the air bubbles by smoothing over with a c/c.
Mine has never come off, but it you change your mind it does peel off if you are committed enough - would be less drastic / toxic than paint and would help it's re-sale value if you ever wanted rid of it.