slowing water thru fuge ?

[AnnetteG]

Does the shut off valve need to be installed on the incoming side or the return side?

Thanks!

[fsn77]

Are you referring to putting a valve on the drain from the display tank? If so, that is generally not a good idea for adjusting flow from the display to the sump / refugium. If a hermit or snail goes down the drain, it could lodge there, creating at least a partial blockage, further slowing the drain and potentially leading to flooding the display tank (and pumping the sump / refugium dry) since the flow from the return pump would remain unchanged. Similarly, flow from the display to the sump / refugium is dictated by the return pump (unless the pump is oversized for the drain). Even if flow is reduced by a valve on the drain, nothing will have changed the amount of water the return pump is moving, which can result in the display tank filling up faster than it can drain, again flooding the display tank.

If you would like to control the amount of flow from display tank to the sump / refugium, one of the better things to do is to "T" the output from the return pump and run the "T" back to where the drain enters the sump / refugium (creating a recirculating loop). A valve on the "T"-ed line that runs back to where the drain enters will allow for control over the amount of flow going back up to the tank.

If the return pump is just generating too much flow and putting a "T" in the line won't solve the issue you're having, it might be necessary to downsize the return pump.

What brand / model of return pump are you currently using?
What size is the display tank? The 105g?
What size is the sump / refugium?
What is happening that there's a feeling there's too much flow?

[Amphiprion]

Why are you trying to slow flow through the refugium? Most people don't have adequate circulation or feed flow into refugia to begin with.

[AnnetteG]

Well, it had been my understanding that the flow through a refugium needed to be really slow. I was told that here, on AC. But after further hunting tonight, I'm seeing the opposite, like you said, that most of the time the flow is not fast enough and even that it should be fast enough to cause my chaeto to tumble around.

Anyway, there isn't anything happening to cause me to think I need to slow the flow, other than what I was originally told when I first converted from wet/dry to refugium. I have a mag 9, so I really doubt I would need to downsize from there. If anything, I think I'd like to upsize.

Anyway, thanks for the explanation! Leaving the flow alone. :)

[Amphiprion]

Ah, I see. I was thinking there was some sort of mechanical issue with the flow, which would be unavoidable otherwise.

Yes, you want good flow rates in the refugium. Circulation is crucial for good growth of macroalgae and really isn't detrimental to 'pod growth, etc. Also, actual feed flow to many refugia is too low, and as a result, it kinda "starves" a refugium due to lack of incoming food.

[madeley]

Here's a great link for a flow control sump, this is what i'm going for when i get around to it.
http://www.reef-eden.net/diy_4.htm