Im surprised its still alive...what is your Ph? They like acidic water more than alkalinity water. It would thrive a lot better in the first planted tank you showed, at least as far as water chemistry goes.
I have read that it can be kept enviroments with a Ph ranging from 6.0 to 8.0, or even higher. However, I would think 7.0 to 7.4 would be best.
It will probobly become pretty aggressive towards the other fish. I had a female for awhile that had a male firemouth and a male convict cowering in a corner.
I have also read conficting information an their natural feeding habits.Seriously Fish states "Although often referred to as an ‘eartheater’ this species isn’t as benthophagous as members of Geophagus though mouthfuls of substrate are sometimes taken and sifted for edible items." while Sam Borstiens site states "'Geophagus' brasiliensis is a omnivore, searching for edibles by sifting through the sand. In an aquarium this fish will accept almost any kind of prepared food. I like spectrum and tetra cichlid sticks as they put weight on the fish and keep them in good condition."
Either way, I would recommend a sandy substrate. Unless something else is necessary for plants.