here're the new photos. click photos for larger version.
i've included a photo of the tank with the cupboard door open, a photo of the top of the tank, and a photo of the canister filter and the denitrator behind the tank and cupboard.
ps: the half buried pebble on the bottom right of the tank (front view) was meant to be the 'bed' for the puffer, and he really sleeps there at night.