A quick update: the SunSun is running well. I got a two more of them (303) one for a second aquarium (50Gal) I started up and one for a low end cichlid tank that has been running for a couple of years...the filters are great!!!
on my 180g I added a supplementary filter which is an atman bio tube (http://photobucket.com/images/atman%...0bio%20filter/
) with 8 canisters that are filled with ceramic rings, bio balls and filter material...same principle as the sun sun but cannisters are packed in a horizontal tube that hangs over the tank...fed by a 2000lph water pump...
I guess with both filters things are moving well. I have good water parameter readings.
thumbs up for the SunSun