what do u guys think? (aquarium background)

[match55]

I was doing a cover up for my DIY stand this morning and came out with a piece of card board that fit right on my aquarium background, so I went to get my art tools and decided to paint my own tank BG.
what do you guys think?
suggestions are welcome, cuz I can always do changes on my painting XD

the reason I paint on the back side of the card board is that my tank is on beside the wall, so I will still be able to see the ugly side of the card board on the back of my tank if I didn't paint it this way.