Big caps in not-so-big tanks equals moderate headache.
This one should be much lower in the tank because of its height (it was much lower to begin with but over 2 years has grown some 10" in height). It's height and overall circumference create some nasty flow and lighting shadows and it's a challenge to work around it. Honestly, mine doesn't belong in my tank anymore, it's far outgrown this current tank and if someone made an offer to trade for something or to buy it, I'd probably be tempted. Frag it and let it start over, that's my advice: i.e., "don't let this happen ... to you."