I have a biocube 29G running with 3 horses.
I am using regular white sand and live rock, with a ball of chaeto tucked into the rockwork. I use a AquaC remora on the back and nothing else for filtration.
The tank houses 2 tigertails and 1 reidi, all captive bred, they are fed twice a day with mysis it is for this reason I opted to add the remora. It helps with waste removal from all the feeding.
The tank also houses 2 purple firefish, 1 yellow watchman goby and a pistol shrimp.
As for corals, I use this tank to mainly house my zoas, palys, rics and yumas. There is also 1 large brain in the mix as well. The tank has been running for quite a while now and I only change the water every two weeks. I usually do about a 2G water change each time. I do occasionally soak the mysis in selcon as well.
Good luck,
Mike