Hi. i also was set to buy a spec but instead went with a 4g pico. The candycanes do actually need light by the way. I'm not sure what if any fish I would put in there. The green clown gobies are tiny, i have one in my pico.
Have you thought about upping the size of the tank? Also, look at how tiny the back filtration unit is, I was deterred by people because of that. It would make working on the tank kinda hard. lol
180g- Mostly BIG fish and some coral. ~80g Nuvo- My coral tank with "happy fish"~ 90g- FOWLR Not the not happy type of fish~ 125g- Freshwater Malawi Cichlids ~10g- Nuvo- The refugees from the Ich of '18