Cool! Brings back memories!
I was a fish nut as a teenager. Even worked in a pet shop. At one point I had 2 55's, a 30, and around a dozen 10's goin in the basement. I had fresh and saltwater.
The technology now is awsome. The best thing to come along when I was doin it was a UV sterilizer. When I had saltwater fish you could sell an established fish back to the shop for a profit!
I solved a few problems in my day. One of my favorite types of fish were trigger fish. The problem was if ya put 2 in the tank together they would fight to the death. Solution...I had I think 8 diffrent kinds of trigger fish in a 55 in my bedroom. They all survived! Them Fr's would wake me up in the middle of the night fighting! Forget about arranging the tank. It was there way no matter what you did. I have watched a 4 inch blue niger triggerfish pick up a 6 inch diameter piece of coral and move it across the tank! Them dudes had some personality too! And yes...I'm sure they had a good bite if ya let them....had an eel one time I had to feed live fish....would usually go through around 10 big guppies trying to get one to the eel. The triggerfish would snap them in half with one bite.
Other rarities for my time I had: A regal angel that would eat!, A huge lionfish that would eat tablet food, and the neatest....a small nurse shark! Did you know if you pick them up they squeel like a pig. I used to go to the river every few days and catch fish to fee him.
Wish I could have a tank now but am away from home too much.