Thanks, My dimensions are 30 L x 12 W x 18 H and my filter is rated for 160L tank and moves 720 L/h according to the box. I just added the 6 blue tetras today and it looks a bit cosy in there so I thought I would ask Hopefully it's ok, I do a 25% WC weekly and I haven't had an issues to date. I'm hoping it will be ok as they are all relatively low bio load fish apart from the guppies as far as I know.
Well I have noticed the new blue emperors chasing the cardinals around a bit actually, and my guppies have been hiding in the plants at the top of the tank. I hope I didn't screw up the peaceful community I had