You should have plenty of pods from the live rock and chaeto - feed the tank a little and give it time. To the full extent possible, I would outfit the main display with plenty of dense cover zones in the same way you are doing the sump - chaeto and/or a little rubble behind most of your rock outcroppings is a good start. (Cheato will survive just fine/make a great cover zone with even with just indirect light.)
If you could encourage some nice hair algae growth, that would probably be one of the most optimal cover zones for them to hunt in - they'd love you for it. Any more flow/cleaner conditions than that and you're going to be completely on the hook in getting him to eat food from the fish store instead.
Any other inhabitants planned? I would recommend against most other tank mates for several reasons - certainly to start I'd recommend against anything that could compete with them for food. Hermits, wrasses, gobies, dragonets, blennies, many snails and anything with star in the name would all be out, for example, and off-hand I can't think of a fish that I'd really recommend to put with them that wouldn't feel like a roll of the dice against the pipefish. I'd add some Cerith snails or limpets you know to be algae eaters from an existing tank and leave it at that....if not forever, at least until they are fully acclimated and feeding strongly for several weeks/months. I might even hesitate on adding coral along the same lines.
Pipefish are tough to acclimate in the first place (to wit, check out
this earlier thread), so if - when! - yours does successfully: A) keep us up to date and B) don't make him compete for space or food! :wink: They do not yet have an awesome record of survival in captivity.
Wish I could offer more advice! Someone else needs to chime in! :xd:
-Matt
