3/4 gallon Nano reef
I remember when I first started in the saltwater hobby I was told that the smallest tank you could do was a 55 gallon and any thing smaller was just to difficult. that was 15 years ago ! So the first thing I did was get a 10 gallon and set it up....  I started with a 250 skilter a few small pieces of Live rock ( Wild Florida live rock) that was back in the day when you could still get that beautiful rock. and a damsel. after the tank cycled I added a small hawk fish and a worm goby(tiny juvenile). Well the tank did great and so I set another one, then a fifteen gallon high and by that time I was trying small pieces of coral like mushrooms ,star polyps,sponges, not to long after that corallife came out with a mini light which i think was the first compact florescent 50/50 about 7 watts I think and I got one of them and the rest is history. By the way the worm goby grew up and by then I moved him into a 75 gallon and he just passed away this passed Feb. he was twelve years old I added a second one about 6 months after the first and he lived for 11 years. Any way....... having said all that  with the nano reef being the rage and all the wonderful products designed to make our lives easier the only thing left to do was to go smaller!
Low and behold Red Sea Fish Farms has just come out with a 1 gallon with a tiny filter (power ) and a clamp on 7 watt power compact lamp!
So I couldn't resist...... Here it is.......
3/4 Gallon
7 watt Pc dayight bulb
Ro/Di water
1 Blue ricordia mushroom
1 orange ricordia mushroom
1 red mushroom
1 blue bullseye mushroom
1 small finger leather
1 star polyps frag
3 brown button polyp frags
1 yellow toadstool leather frag
1 yellow button polyps frag
1 gonipora (flower pot) spawned from a big  one in our 120 gallon reef
1 scarlet hermit crab
3 tiny pieces of figi live rock
1 feather duster
1 small halimedia plant
1 hand ful of carib sea live sand