I use to have 4 tanks, one 120 gallon, one 54 gallon corner bow front, one 29 gallon, and one 20 gallon. I use Marineland Bio-Wheel filters. Now that I moved, I have only the 54 gallon :(
Keep up with water changes and DON'T OVER-FEED. I only feed once a day. Don't use cheap filters.
The pet trade gets a bad rap for exploiting wild animals but sometimes the opposite is true.
Modern advances in technology affect every industry - even the aquarium hobby.
If you are looking for a unique invertebrate to add to your saltwater tank, consider the sea urchin.