Okay so I had this tank up and running for about ehh 4 months now. problems are slowly turning up. I have two Oscars in a what was supposed to be a 75 gallon tank. The measurments of the tank are 4 foot long by 2 1/2 tall by 13 inches wide. The measurments don't really match a 75 gallon.

Very weird, the really annoying this is I doubt it is barely a 55 gallon. Any who, I want to redo it. I'm donating my fish in there this LSF that I found the other day, and i'm starting right past the step where you have to cycle the tank. I'm adding more sand ( i didn't really add enough in the first place), and I want to put in some caves driftwood rocks and moss.
I want to have fish that are clam and nice with each other, but also have energy. I want something common with Oscar, but not the bioload of the big guy. Down the Cichlid road. I also want shrimp and maybe a snial. I don't really want plants in the tank because I feel like they would die on me (knowing my luck). If any plants that I would think about getting, would be low light plants. i'm not trying to do that
co2 system. Plants that could survive on a hood lights and a small amount through the window. I know I kinda limited myself with everything i've said, but if you guys could throw out ideas that would be fantastic. I need your guys full support, this is my first attempt at a planted tank. Call it a build thread in a sense. I know so many of you like those haha.