I have a 3 gal pico tank, I keep things very very simple. I run a tiny hob filter deco type on my tank, heater, moon light, 9" coralife 9 watt 10,000k and 9 watt true actinic fixture. No sumps or powerheads.
I have a sand bed, Florida Ricordeas, Sun Coral, Green Star Polyps, Button Polyps tiny...