Minimum flow through activated carbon

[CMO]

I see a lot of references to carbon flow rates being described as "low" but can't find much guidance in terms of gph. I'm running a flow meter on my carbon and would like to set it to the lowest effective flow rate (since it's running off my return manifold and I want as much circulation back to DT as possible) but not sure what that is. I'm running a BRS 3 cup reactor with rox 0.8 on my 165 gallon tank. Would about 50 gph be adequate flow through the reactor? I'm running 24/7.

Thanks

 

[DesertReefT4r]

Min I would say 200 gph through the carbon. I like get enough flow to get the carbon to suspend but not tumble in the reactor. If it tumbles it will be broken up and end up it the water colum.

 

[CMO]

So what might the logic be behind needing a bit higher flow like 200 gph? If I ran slower flow wouldn't it just take a little longer to clear up the water? Also, I wonder if people really know how much flow they're getting out of their pumps without running flow meters. I was running a varios S2 on 1/2" line with Neptune flow meter and only getting about 150 gph on max speed (pump is rated for for 792 gph). Based on this, I imagine people running reactors with something like an MJ 1200 rated at 295 gph aren't getting upwards of 100 gph.

 

[Forsaken77]

Min I would say 200 gph through the carbon. I like get enough flow to get the carbon to suspend but not tumble in the reactor. If it tumbles it will be broken up and end up it the water colum.

Typically you don't run carbon like that in a reactor. You should use the 2 foam pads and sandwich it tightly packed together to prevent movement and channeling. It WILL crumble to some extent if it's moving at all. You want it tightly packed towards the top of the reactor.

 

[mta_morrow]

Typically you don't run carbon like that in a reactor. You should use the 2 foam pads and sandwich it tightly packed together to prevent movement and channeling. It WILL crumble to some extent if it's moving at all. You want it tightly packed towards the top of the reactor.

Agree. Use the pads top and bottom, no tumbling. Low flow.

And after about 3 days it’s used up.

I run carbon as describe above for 3 days a month