Hello :0 This is a guide to help with stocking biocube.

[Wet Nerd]

I am def. no expert. I have 3 month experience in the saltwater hobby, but i have researched and experimented with stocking much. A FAQ i always see is something about stocking a biocube. This guide is not set in stone, as some people are conservative stockers but here you go.
List (i obviously am not including some) do research first of course not all reef safe. Sorry for the poor writing, i just want a quick guide.
Valentini puffer
clownfish (perc and occ)
gobies
cardinals
damsels, chromis
dart fish
royal grammas or basslets
chalk bass
fire or skunk shrimp
peppermint shrimp
pistol shrimp
sexy shrimp
cb shrimp
flame angel (most dont reccomend)
dragon face pipefish (they are absolutely fine in a 29, trust me. The problem is not space, it is food. Stock with pods. Most cant feed them so do with caution)
mandarins ^ exact same.
Clown gobies.
Emerald Crab.,
Pom Pom crabs.
Tons of more inverts.
How much to stock?
I reccomend no more than six fish. I currently have six small fish and territory issues are none, same with nitrates. If you chose "big" nano fish, i'd go four. Remember, large inverts DO put toward bioload a bit.
An example of a stocking list

One fire goby, pair of clowns, royal gramma, chromis. Five fish. Good.
Thanks for reading.

 

[Wet Nerd]

Also, i purposely did not put six lines in here. Cubes aren't that great for six lines because they are super fast and like long tanks. They are also very agressive in cubes.

 

[DaveK]

A few additional observations on your list.

Puffers love to eat things like shrimp and crabs, make a choice as to what you want.

I'd leave out damsels unless all you want are damsels. When they get larger they tend to get really nasty.

Dragon face pipefish. I'd say a 29 gal biocube is a bit small for these. Your going to need about 50 gal of water so the tank will produce enough pods for them. Also, most other fish will out compete them for food. This is a really difficult fish, so only consider one if your really sure about what your doing.

A few others I would add -
Jawfish yellow hear or bluespot
Hawkfish, spotted, falco, longnose, geometric pygmy These will eat shrimp and small crabs
Harlequin bass
Pajama cardinal and Banggai cardinal Other cardinal species are good too
Many other small SW angles are good, but some may eat corals, so have a plan if it doesn't work out
Dottybacks add one last since they are a bit more aggressive