Well thats true. Do stuff to fast it wont work out. I have every thing I need to set up the tank except for the carbon+bacteria. I was going to use a filter rated for a 40-55g tank which the flow rate is 200gph. So I would need the whisper20 rated @ 106gph? Or heres another Idea

The water would just over flow into the first chamber where the MJ would force water through a bag filled with carbon into section 2 ( there would be big holes in the baffel between sec 1 & 2) then the water would be pumped back into the tank by the MJ.
Would that work instead of using the HOB?
29G Mixed tank, 380w of light (250w 14k Ushio, 2x65w PC Actinic), Octopus NW110, 75x turnover.
Finally after years I have a tank worth showing!