Oh, I wanted to post a list of do's/don'ts:
- Don't do an internal overflow - makes cleaning very difficult.
- Don't do 'through-tank' returns, go overtop (have had the ball valves stick open once).
- Don't do coast-to-coast style without some sort of screen/mesh - angelfish do not like the sump trip, and rescuing everything else is a pain.
- Do have lids for the display tank and sump to prevent the majority of evaporation - saves a lot of refill maintenance.
- Do stick with one breed of fish rather than a bunch of different ones, looks nicer IMO.
- Do spend more time on the aquascape plan.
- Don't forget that the gravel/mts takes up 1-2", so plan rock display accordingly.
- Don't go small on the sump...30G I'm thinking is the smallest you'd want a sump from a purely practical point of view (maintenance, access, etc)
- Do get a lot of plants to start, key for getting cycled and keeping the water levels in the green.
- Do make your sump cover easy to remove.
If there's ever a catastrophe or we move or some such, I think we'll be moving to a 180G at minimum...most likely a plywood tank. 55G is so small!