I used to have a couple tanks years ago, 15 or so, before camera phones & ease of Internet access so no pics. I lived with my parents still & had a couple saltwater tanks. One was a 20 gallon with live rock, a bunch of corals, crabs & snails to help maintain it, & a few fish a clown, gobbie, a mean ass wrass, & a blue tang. Don't remember all the specific corals I had, but remember there was a brain I was proud of, some polyps, & a clam that died, rotted, & stunk bad when I took it out. The tang eventually got to big for the tank & had to sell it off. I also had a 20 gallon long predator tank with live rock, a snowflake eel, a trigger, & a puffer, & snails & crabs. They eventually outgrew the tank & I gave them away, & got out of the hobby. As far as filtration & lighting, I just used the filters that hang on the back of the tank & the hood style lights with florecents & suction cup power heads that were readily available back then & it worked well with the smaller tanks Never needed heaters with room temps staying in the high 60s low 70s. I had friends with their own houses with larger tanks, 55 - 300 gallons with sump tanks, but I didn't have room for that at the time. We got all of our corrals, fish, etc. at the time, from a guy that had four baptism pools converted into tanks in his shop in a neighboring town. I actually think that he & some of his friends poached um occasionally from reefs along the gulf. Don't really know & didn't really care back then. That was what we had available & the price was right.