My New 72"x20"x20" Tank Build

[GreenSpottedPuffer]

Originally Posted by untamed

I have 4 separate Herbie overflows in my system and they are all inter-related. Any change to any of them affects the others.

Yes, start up with the gate valve wide open. It will be noisy and the water level in the overflow box will be right on the bottom. That will prove to you that you've designed with excess capacity.

Next test: Shut the gate valve 100% closed. This will test your emergency overflow. This is the test that will make you nervous as the overflow water level rises up to that emergency level. You need to know for sure that the emergency overflow can take ALL the volume. Be ready to stop the return pump, or open that gate valve fast....just in case. (and make sure that the emergency overflow actually has pipe connected to it!!!!)

When you go to fine tune things, you'll find that small changes to the gate valve make a difference. It also takes a while for the system to equalize after a change, so adjust slowly.

Ok that all makes sense but what about getting the refugium herbie and main drain herbie working together? It seems like it would be hard to work on fine tuning both at the same time, especially if you are starting with both wide open. I guess Im just a bit nervous. If it were just the overflow using a herbie, I would feel fine but the refugium one worries me.