There is two way's to plumb the tanks first is you will need to drill the tank (DT) and use what is called bulk heads you can find them online or at LFS. This method for a glass tank is the best. Second way is by using a over flow box there are two pieces to this one of them the shorter one sits inside the tank(DT) and the other part sits on outside and hangs on back style and uses a u shaped pipe that you use. The way you siphon the is by using a air line tube and with the u tube in the water from both side you slip the tube in it to where the air is at in top of tube and suck the air and the water starts flowing the only problem with these is if any air bubbles go into the cup and into the u tube it will stop the suction so you will have to make sure that this is far away from that problem but they work great and you won't have to drill the tank. The idea you have for three chambers is great if it's glass then you should use glass but you can use plexI but may not last as long due to the plexI flexes and can cause the aquarium silicoln to give unless you use a 1/2 inch thickness. I f you look at my pics in my profile and see some of the sumps that I have built you may get a better picture but I build mine with certain chambers and requires a lot of work and planning. So any way's the inlet going into sump from DT can either be just layed into where water will be in sump or you can make a lid and use a bulk head and you can continue the pipe into the sump and be able to cut it at whatever size. as for the return for the pump again you can drill or use a return flow that stradles the tank lip. Big factor here: If you drill use 1 1/2 inch tubing for inlet to sump and use 1/2 inch for return if you use this you will have no problems. If you choose the over flow box style use 1 inch inlet and 1/2 inch return.D_Ahumada said:The stand I currently have has a space beneath the main tank area that I will be able to put the second tank.
I'm not entirely sure how to plumb the system. I was thinking of dividing the second tank into three sections, one for the inflow, one for the refugium and one for the return. Does this make sense? It is an all glass tank, and so I'm wondering can I use plexI to divide the sections or do I need to use a glass and a silicone to seal it?