Questions about peacock mantis

[Moogled]

Some say that you'll want to keep a Peacock in a 33 but for a 2 incher, a 20 gallon will do fine for a long time unless your mantis grows to a monster size. Unless you're planning to keep low maintenance corals in with the mantis, corals would be a bad idea as mantis shrimp often like to move things around in the tank. Furthermore, they do not appreciate the high intensity lighting that some corals do - fluorescent bulbs will do fine.

If you want to pretty up the tank, use macroalgae for a decent effect. Some mantis shrimp like p.ciliata like to play in it.

Keep in mind that mantis shrimp are very messy eaters; they'll probably eat about 1/4 of a piece of shrimp and dump the rest. Polluted water from uneaten food + high lighting are both contributors to mantis shell disease.

Most smashers are resilient so just shove an Aquaclear for circulation and maintain water quality by removing uneaten foods/water changes. A skimmer is a definitely plus but not necessary.