To plenumn or not?

craigwol · 11/22/2006, 10:03 PM

I'm starting a 120 gal and the main tank willl have a shallow (1 to 2") of aragonite sand.

I'm going to have an approx. 15 gal refugium in the sump. Would there be any benefit for having a pelunum with a DSB (4+ inches) in the refugium.

I was hoping to get the de-nitrificaion effects of the DSB with a minimal risk for it crashing.

Is such a small DSB and plenumn worth the effort?

Thanks in advance.

Craig

Dr.FuManchu · 11/23/2006, 01:06 PM

Not! Plenum=Old School

Use plenty of live rock 1.5- 2 pounds per Gal, and good water flow at least 30 times tank volume turnover and a good skimmer rated for a larger tank than you have.

Randall_James · 11/23/2006, 02:51 PM

You can just put in a good 6"+ sand bed in the refugium. Life span should be good for 3-4 years without fear of any issues. I have seen a growing number start putting the sand in 3 sections and replacing 1 each year.

another option is using a 5 gallon bucket full of substrate and with enough flow to keep detritus from settling in it. The bucket is esentially filled with sand and plumbed in and out. Put the lid back on, give it no light and for around $20 you have a remote deepsand bed.

WaterKeeper · 11/23/2006, 03:30 PM

Craig,

Repeated experiments have shown little value in having a plenum. In fact, if the bed depth over the plenum is too shallow, it can cause problems according to some recent research. As advised, just stick with the plain DSB.

11/22/2006, 10:03 PM	#1
craigwol Registered Member Join Date: Nov 2006 Location: Montreal, Quebec, Canada Posts: 31	To plenumn or not? I'm starting a 120 gal and the main tank willl have a shallow (1 to 2") of aragonite sand. I'm going to have an approx. 15 gal refugium in the sump. Would there be any benefit for having a pelunum with a DSB (4+ inches) in the refugium. I was hoping to get the de-nitrificaion effects of the DSB with a minimal risk for it crashing. Is such a small DSB and plenumn worth the effort? Thanks in advance. Craig

11/23/2006, 02:51 PM	#3
Randall_James Premium Member Join Date: Feb 2005 Posts: 6,727	You can just put in a good 6"+ sand bed in the refugium. Life span should be good for 3-4 years without fear of any issues. I have seen a growing number start putting the sand in 3 sections and replacing 1 each year. another option is using a 5 gallon bucket full of substrate and with enough flow to keep detritus from settling in it. The bucket is esentially filled with sand and plumbed in and out. Put the lid back on, give it no light and for around $20 you have a remote deepsand bed. __________________ "It's a dog eat dog world and I feel like I am wearing milkbone underwear"

11/23/2006, 03:30 PM	#4
WaterKeeper Bogus Information Expert Join Date: Oct 2000 Location: SW Ohio Posts: 16,147	Craig, Repeated experiments have shown little value in having a plenum. In fact, if the bed depth over the plenum is too shallow, it can cause problems according to some recent research. As advised, just stick with the plain DSB. __________________ "Leading the information hungry reefer down the road to starvation" Tom Current Tank Info: 130 Now out of service and a 29

11/23/2006, 01:06 PM	#2
Dr.FuManchu Moved On Join Date: Jul 2004 Location: Northern VA Posts: 257	Not! Plenum=Old School Use plenty of live rock 1.5- 2 pounds per Gal, and good water flow at least 30 times tank volume turnover and a good skimmer rated for a larger tank than you have.