If you could - re: circulation

[mark]

If doing a CL, can design so returns aren't noticable (see OM picture forum), something a little harder with PH unless using something like a Tunze rock.

PH and CL can both also give noise. Might get a overall higher flow with PHs than a external pump for the same noise level if not running a separate fish room (do find my Dart though ok for being under the tank).

My tanks been up for a couple years with a CL and still no regrets.