I also have a bc29, and heres what ive built. I am waiting on my chaeto still (it has dividers so you can add siporax too!)
I have done a fair bit of research on how to put a sump/refugium on a biocube29 and unless you arent using a stock hood almost all the overflows do not fit.
What i did was piped a line to the return in chamber 1 where i keep my heater behind the screen. I then piped it to the reactor. Piped the pump on the supply side of the reactor to "suck through" the reactor. I originally placed the supply back into chamber 3 with the main pump but found that lowered the flow through chamber 2. I cut a small hole in the back of the divider and piped down a locline with a Y splitter and aimed the flow right down the back of the tank on a Y pattern.
I am going to go entirely chaeto when it finally arrives and im stocking the chaeto with some pods from copepods.ca
If you wanted to have the bioballs it has a perforated false floor where u can seperate chaeto/macro from your bioballs/siporax
I am using the 550 reactor from two little fishies
Hope this helps! If you arent in a rush ill post my build in a bout a week or so.
Most people use "clamp on lights" which are essentially just a bulb casing with a clamp on the other end.