willra said:
Lookin great. I really like those returns in the bottom corners, it seems like it would be great flow for an anemone.
Some constructive criticism.
Not to rain on a great thread, but I (for one) really
do not like those returns in the bottom corners for many reasons.
Firstly, the best place to agitate water is at the surface, and the best way to do it is with returns from the main pump. In the event of a power failure, only the first few top inches of water will drain to your sump if returns are kept near the water's surface.
Secondly, Haddon's anemone will not like the water flow from such low returns- you'll most likely need to keep them pointed away from the anemone.
Thirdly, I know you have a check valve, but what if it fails?
It does not appear your sump has enough capacity to catch all of the water that will drain from your aquarium. If the check valve fails, all water above the top of those returns will drain to your sump.
With check valves there is also a phenomenon know as the "hammer": water pressure rushing downward causes a rapidly closing check valve to bounce off of the internal seal repeatedly (which sounds like a hammer pounding) and the result is a slow draining of the aquarium. (I've seen this happen personally.)
In my opinion and from years of personal experiences-
never rely on a check valve.
Great looking cube!