[mastergunsg]

I'm currently putting together a 90g 36x24x24 1/2" glass.Ill be using a blueline hd 30x (600 gph a 6' of head) for the overflow pump and a sequence Dart for the CL( i can restrict the flow if needed). I am wondering about number of holes and placement for the Cl. I do not want any lines coming up over the top of the tank. I'm installing a glass overflow box 13x4" foot print if looking down from the top of the tank centered on the back,with 2 holes for a silent overflow. As its made of 1/2 glass as well it sould offer some support for the rear glass. There Is currently 2 holes for 1" bulkheads on the back of the tank up hi in the corners that i will be using for the return lines for the CL. I will be drilling 2 more holes just below them for the Intake's for the CL they will be 1 1/2" bulkheads. Is 2 1 " returns enough for the flow of the dart, or do i need more holes? If so where to place them and the return line/lines for the sump return? I read somewhere you want to keep lines up as hi as possible and do not want them on the bottom so if you do get a leak somewhere you dont drain the whole tank. Sound advice? How close together can i drill holes in 1/2" glass?