I have the BC29 with the 4.36 lighting upgrade. My temps normally hit about 82-83 after a full day of light (that was before my heater, now my photoperiod will start with a water temp of about 79 rather than 76). Im looking for something that can get these temps down about 2-3 degrees and at the same time get quieter than the fans used in the upgrade (they are crappy 10mm thick ones). Id really like to do a 80mm fan in there but it looks like the fan on the right side would be a very very tight fit, if it fit at all. Just because of that shroud that goes around the stock fan. I think it would take some dremeling. Id like to keep the cutting to a minimum if possible but its still an option where necessary. Has anyone upgraded to a quality fan thats quiet and better flowing than stock? Any 60/70/80mm fan is an option at this point. Im looking for someone thats done it already, a forum and google search has resulted in little.