Hey brother, a 2x4 vertical brace behind the door brace panel should support the front of the stand and tank. Instead of cardboard or wood shims use the plastic shims from hardware store. One day at a time and we can get through almost everything.
Glad to see it set up. Keeping a single Oscar would eliminate any aggression problems plus considering they do get large. If your set on wanting a tank mate, I'll suggest a Blood Red Parrot, they have a personality like an Oscar. Or maybe a Gold or Red Spotted Severum, they do get large though. Other fish to consider would be Electric Blue Acara or Firemouth since I know you've mentioned the Firemouth before.
Really great set up brother, tank looks great. For one oscar it will fill up the 55 by himself in no time and maybe need a 75 or larger in the future but idk what other tanks you have right now. I think that gravel and rock set up is really great by the way it looks good
Looks like the problem is the stand is warped and that is likely why it was thrown out. I wouldn’t use it, spend some money and buy a new stand or you tank may crack from stress over time.
great to c it up and running. one oscar would be boring do the planned south american cichlid community but if i may suggest a few jewel cichlids. they r african but act more like SA and behave similar plus a few fast movers among those slow ones really highlights them
I thought you were gonna place the neoprene or yoga mat underneath, I think it would be more effective than the felt pads. Oh and a single Oscar would be dope.