Red Sea overflow

[Calireefer92]

hey has anyone every put a gate valve on the overflow pipe on a Red Sea reefer? And if so what do I need and how to do it?

 

[DLHDesign]

You should not block the emergency overflow drain. The point of this drain pipe is to allow a free flow of water in the case of an emergency - such as a clogged main drain pipe. Without that emergency overflow being wide open, it's possible that the tank could overflow and flood your room.
There should be a valve on the primary drain that allows you control the return flow rate?

 

[Calireefer92]

You should not block the emergency overflow drain. The point of this drain pipe is to allow a free flow of water in the case of an emergency - such as a clogged main drain pipe. Without that emergency overflow being wide open, it's possible that the tank could overflow and flood your room.
There should be a valve on the primary drain that allows you control the return flow rate?

I mean the main drain. I would to put a gate valve because I’m always having to adjust the Red Sea one

 

[DLHDesign]

Ah; I see.
The plumbing is metric (versus the US "standard"), so you either have to get a conversion adapter or you can use the standard fitting and a lot of plumbing tape on the threads (12-15 wraps or so generally works). Once you have that in place, you would build out the gate valve as normal (gluing 1" PVC together to get the return back to the sump via the gate valve).