Plenum versus Refugium

Scuba Steve · 09-17-2007, 11:45 PM

G'day fellow aquarists

Can someone please explain the difference between a plenum and a refugium. I believe I have a plenum. Which is better and if the refugium is more appropriate is it possible to convert a plenum to a refugium or vice versa? Thanks in advance

Scuba Steve

prow · 09-18-2007, 12:07 AM

you can have both if you like. all a plenum is, is a small voided space that is covered under sand. all a refugium is, is a detached/seperated area where you can grow/culture pods and such where preditors can not get to them.

framerguy · 09-18-2007, 12:15 AM

Advanced Aquarist's Online Magazine - Feature Article: An Experimental Comparison of Sandbed and Plenum-Based Systems: Part 2: Live Animal Experiments
this site was given to me when I was asking about plenums. I found it interesting.

Raf · 09-18-2007, 02:00 AM

essentially they both are used to break down nitrates....IMO, the refugium is easier and provides other benefits...

kimoy · 09-18-2007, 09:36 AM

plenum is supposed to be 10% of your total tank area but that is just based on what i heard and that is not the rule i followed. if you are just setting up, i would make my display tank a plenum and your fuge too. for me i just added a fuge with 2 layers of sand on top of an eggcrate (eggcrate = screen = sand = screen = sand) for a total of 6 inches deep. got my nitrates from 50 down to 0 in a about less than a month.

BigAl07 · 09-18-2007, 09:52 AM

I've heard some pretty bad stories about plenums going bad. Note I say HEARD as I've never had a plenum myself. I do have a FUGE and honestly I wouldn't run a tank without one again. The benefits of the FUGE are tremendous and the drawbacks are NONE. In addition to nutrient export you also get the benefit of a budding and growing POD population ( I like to call it a PODpulation) which will also benefit your whole tank. Many Fish LOVE pods and some species dine on PODS exclusively. An added benefit is that the FUGE is really cool to just sit and watch. Many nights I have caught myself looking into the FUGE at the various life forms swimming and playing in there and not the Display Tank. IMHO a FUGE is MUCH more than just an option.... it's PART of the total reef.

Good luck and HAPPY Reefing

Allen

prow · 09-18-2007, 09:03 PM

most plenums troubles are caused by critters in the sandbed. you need a good 3-4" of undisturbed substrate on top of the voided space. small micro screens work great in preventing the critters from burrowing down and exposing the voided space to higher levels of O2 and releases all the bad stuff back into the water.

Rcpilot · 09-20-2007, 11:39 AM

I almost built my reef with a plenum and piping for controlled plenum wasting (CPW). I just couldn't find enough info about it to make me want to risk it. If I'd felt comfortable with it and had read success stories of CPW being used over very long periods, I would have done it in a heartbeat.

Essentially, you build an elevated sandbed over the top of a piping system. The piping system has holes drilled all over in it. It has screen wrapped around the pipes to prevent clogging. You either drill the tank down low on the side-- or have a tank custom made with a hole in the bottom--or pipe it up the back of the tank and then back down. Install a valve lower than the bottom of the tank.

You "waste" or purge the plenum on a set schedule. Weekly or monthly or whatever. You'd have to experiment to find out what frequency would work best for your tank.

The idea is NOT to pull oxygenated water down through your DSB. That would crash it almost instantly. The idea is to open the valve and create a sudden and massive suction that will pull out "liquor" from the lowest part of the plenum. The articles I read, the guy was pulling off a quart about once a week. I think it was about 300g tank, if my memory is correct.

Supposedly, the benefit of this, is that your DSB never turns into a garbage can that never gets emptied. You just slowly purge and pull all the waste right through it and "waste" the liquor out the bottom.

The idea sounded good to me, but it also sounded like you could really mess up if you pulled too much through the bed and introduced oxygen to the lower layers.

I run a refugium on my 30g tank. It's a CPR HOB w/skimmer built in. Capacity is 4.6g-which I think is quite a lot for a 30g tank. I think this fuge would easily handle a 55g or 75g tank. My DSB is about 4.5--5" deep. I love it. Does just exactly what I wanted it to do. Grows pods. Grows cheatomorpha. Filters out nitrates and phosphates. I have about 2lbs of rock rubble in my refugium.

Scuba Steve · 09-20-2007, 08:35 PM

Ok....thankyou everybody thus far. Rcpilopt your reply was most interesting. Is it possible to convert my existing plenum located in my sump to a refugium? And if so.....how please?

reefman420 · 09-20-2007, 08:46 PM

i personaly wouldnt touch it.unless u havnt hd it running for a long time.the possibility of releasin all that junk scares me.rc pilot if u think ure hang on is good on ure 30.I hav a 20 gallon with 4 inch dsb.and it rocks.i wonder how big a system this would work 4.I would love to just stop drainege and hook it up to my big tank when i upgrade

prow · 09-20-2007, 08:46 PM

mmm, if your plenum is in the sump then it is already a refugium aswell. if your plenum has a sand bed with a screen to prevent critter from burrowing down to the plenum just add a couple peices of LR some macros add a light puff, you got a exporting pod cultivating refugium

FYI. most public aquriums employ a plenum.

Scuba Steve · 09-23-2007, 08:44 PM

Does it need to be a particular type of light? And does the sand bed need to be a certain depth?

09-17-2007, 11:45 PM	#1 (permalink)
Scuba Steve Bryozoan Join Date: Apr 2004 Location: Sebastopol Posts: 40 View Gallery Karma Komment Add yours!	Plenum versus Refugium G'day fellow aquarists Can someone please explain the difference between a plenum and a refugium. I believe I have a plenum. Which is better and if the refugium is more appropriate is it possible to convert a plenum to a refugium or vice versa? Thanks in advance Scuba Steve

09-18-2007, 12:07 AM	#2 (permalink)
prow Manta Ray Join Date: May 2005 Location: Redondo Beach, CA Posts: 3,854 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium you can have both if you like. all a plenum is, is a small voided space that is covered under sand. all a refugium is, is a detached/seperated area where you can grow/culture pods and such where preditors can not get to them. __________________ "He who sees things grow from their beginnings shall have the finest view of them" ........Aristotle........ "The only difference between me and a madman is that I'm not mad." - Salvador Dali my chronicle........ http://www.reefsanctuary.com/forums/...al-system.html

09-18-2007, 12:15 AM	#3 (permalink)
framerguy Manta Ray Join Date: Jun 2007 Location: Mount Airy, Ga Posts: 3,326 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium Advanced Aquarist's Online Magazine - Feature Article: An Experimental Comparison of Sandbed and Plenum-Based Systems: Part 2: Live Animal Experiments this site was given to me when I was asking about plenums. I found it interesting. __________________ ___________________________________ Greg All time fav quote: "Now and then it's good to pause in our pursuit of happiness and just be happy."-Guillaume Apollinaire "Being happy can be as easy as deciding to be!"-Greg Kimsey (framerguy) Still Workin' on it! 390gDT built in wall, Gargantuan DIY Beckett Skimmer, 150g sump, Sequence Hammerhead closed loop, 75 gallon seagrass/mineral mud refugium, 55 gallon crushed coral/live rock refugium, 30 gallon DSB/ cheatomorpha refugium, algae turf scrubber, DIY calcium reactor, DIY kalkwasser mixer, DIY light system w/4x 250MH & 4x54w T5, etc, etc, etc... chronicles-akwareum (\___/) This is Bunny. (=O.o=) Copy and paste him into your signature (")__(") to help him gain world domination

09-18-2007, 02:00 AM	#4 (permalink)
Raf Scopas Tang Join Date: Jan 2007 Location: N. Vancouver, BC Canada Posts: 431 View Gallery Karma Komment	Re: Plenum versus Refugium essentially they both are used to break down nitrates....IMO, the refugium is easier and provides other benefits... __________________ Our Photos: Nikon D70 w Nikkor 60mm 2.8d micro http://www.aquaticescapes.ca Check out our Malawi site: http://www.malawimayhem.com Cheers Raf & Diana

09-18-2007, 09:36 AM	#5 (permalink)
kimoy Sea Pen Join Date: Feb 2007 Posts: 338 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium plenum is supposed to be 10% of your total tank area but that is just based on what i heard and that is not the rule i followed. if you are just setting up, i would make my display tank a plenum and your fuge too. for me i just added a fuge with 2 layers of sand on top of an eggcrate (eggcrate = screen = sand = screen = sand) for a total of 6 inches deep. got my nitrates from 50 down to 0 in a about less than a month. __________________ 1.20 G pico RR with 2 megaflow kits, aqua c EV180 with mag12, 2x250 DE 12k halides with 2x54 T5 actinic+, 30G phlenum fuge with chaeto, iwaki 55rlt return pump connected to a sea swirl, 4 tunze 6025 inside the main tank for water circulation (2 are modded) 3 Koralias PH(2 #4's and 1 #3) sps,lps,zoas,softies,pink tip BTA tangs - yellow, unicorn, blue hippo, palini and RS Purple Blue Spot Jaw Fish red lyretail anthias pair of spotted mandarin goby wrasse - yellow corris scribble rabbit fish Clown Fish -3 percula high fin shrimp goby clean up crew - various snails and crabs, red linkia star And a 30G AGA softies with clown & diamond head goby

09-18-2007, 09:52 AM	#6 (permalink)
BigAl07 Reef Addict (hopeless) Join Date: Mar 2007 Location: Waynesville, North Carolina Posts: 10,619 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium I've heard some pretty bad stories about plenums going bad. Note I say HEARD as I've never had a plenum myself. I do have a FUGE and honestly I wouldn't run a tank without one again. The benefits of the FUGE are tremendous and the drawbacks are NONE. In addition to nutrient export you also get the benefit of a budding and growing POD population ( I like to call it a PODpulation) which will also benefit your whole tank. Many Fish LOVE pods and some species dine on PODS exclusively. An added benefit is that the FUGE is really cool to just sit and watch. Many nights I have caught myself looking into the FUGE at the various life forms swimming and playing in there and not the Display Tank. IMHO a FUGE is MUCH more than just an option.... it's PART of the total reef. Good luck and HAPPY Reefing Allen __________________ Allen Allen's testimonial . . ."Let Me help you help YOURSELF" (Click Here) with a SW set up there is one basic fundamental rule that we ALL should follow *When in doubt... wait it out. This means take it slow and let the tank "develop" and don't rush it. Time is your friend Ask me about how to increase your REEF budget without going without FOOD!!* Big Al's 10g Julie's (BigAl's Gal) 6g NanoCube BigAl's Slow 90g Tank Chronicle Allens OFFICE 12g Nano-Reef Reef Balls & Cakes Debt Free & Change your Family Tree!!

09-18-2007, 09:03 PM	#7 (permalink)
prow Manta Ray Join Date: May 2005 Location: Redondo Beach, CA Posts: 3,854 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium most plenums troubles are caused by critters in the sandbed. you need a good 3-4" of undisturbed substrate on top of the voided space. small micro screens work great in preventing the critters from burrowing down and exposing the voided space to higher levels of O2 and releases all the bad stuff back into the water. __________________ "He who sees things grow from their beginnings shall have the finest view of them" ........Aristotle........ "The only difference between me and a madman is that I'm not mad." - Salvador Dali my chronicle........ http://www.reefsanctuary.com/forums/...al-system.html

09-20-2007, 11:39 AM	#8 (permalink)
Rcpilot Has been struck by the ban stick Join Date: Sep 2007 Location: Arvada, CO. Posts: 297 View Gallery Karma Komment	Re: Plenum versus Refugium I almost built my reef with a plenum and piping for controlled plenum wasting (CPW). I just couldn't find enough info about it to make me want to risk it. If I'd felt comfortable with it and had read success stories of CPW being used over very long periods, I would have done it in a heartbeat. Essentially, you build an elevated sandbed over the top of a piping system. The piping system has holes drilled all over in it. It has screen wrapped around the pipes to prevent clogging. You either drill the tank down low on the side-- or have a tank custom made with a hole in the bottom--or pipe it up the back of the tank and then back down. Install a valve lower than the bottom of the tank. You "waste" or purge the plenum on a set schedule. Weekly or monthly or whatever. You'd have to experiment to find out what frequency would work best for your tank. The idea is NOT to pull oxygenated water down through your DSB. That would crash it almost instantly. The idea is to open the valve and create a sudden and massive suction that will pull out "liquor" from the lowest part of the plenum. The articles I read, the guy was pulling off a quart about once a week. I think it was about 300g tank, if my memory is correct. Supposedly, the benefit of this, is that your DSB never turns into a garbage can that never gets emptied. You just slowly purge and pull all the waste right through it and "waste" the liquor out the bottom. The idea sounded good to me, but it also sounded like you could really mess up if you pulled too much through the bed and introduced oxygen to the lower layers. I run a refugium on my 30g tank. It's a CPR HOB w/skimmer built in. Capacity is 4.6g-which I think is quite a lot for a 30g tank. I think this fuge would easily handle a 55g or 75g tank. My DSB is about 4.5--5" deep. I love it. Does just exactly what I wanted it to do. Grows pods. Grows cheatomorpha. Filters out nitrates and phosphates. I have about 2lbs of rock rubble in my refugium.

09-20-2007, 08:35 PM	#9 (permalink)
Scuba Steve Bryozoan Join Date: Apr 2004 Location: Sebastopol Posts: 40 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium Ok....thankyou everybody thus far. Rcpilopt your reply was most interesting. Is it possible to convert my existing plenum located in my sump to a refugium? And if so.....how please?

09-20-2007, 08:46 PM	#10 (permalink)
reefman420 Elegance coral Join Date: Jul 2007 Location: minneapolis Posts: 1,085 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium i personaly wouldnt touch it.unless u havnt hd it running for a long time.the possibility of releasin all that junk scares me.rc pilot if u think ure hang on is good on ure 30.I hav a 20 gallon with 4 inch dsb.and it rocks.i wonder how big a system this would work 4.I would love to just stop drainege and hook it up to my big tank when i upgrade __________________ 155 oceanic bow front,20 long refuge packed with caluerpa and mangroves,40 gallon sump,175lbs LR,3x250 watt xm 10ks,aqua-c remora,and pro-clear 150 skimmers sailfin tang,kole tang,royal gramma,cinnimon clown,2xpink skunk clowns,six line wrasse,mandarin, 155 bow coral-orange montipora cap,superman monti cap,scripps green polyped staghorn,ORA pink poccilipora,ORA blue millipora,green slimer,yellow UK acro,pink birdsnest,armor of god zoas,various zoas and shrooms,hammer,frogspawn,clove polyps,favite,fancey toadstool,reg toadstool,yellow leather,purple leather,devils hand,2 types xenia,ricordea florida,ricordea yuma,kenya tree,galaxia,bubble coral,button polyps inverts are lots of snails and hermits,crocea clam,maxima clam and seabae anemone,rbta

09-20-2007, 08:46 PM	#11 (permalink)
prow Manta Ray Join Date: May 2005 Location: Redondo Beach, CA Posts: 3,854 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium mmm, if your plenum is in the sump then it is already a refugium aswell. if your plenum has a sand bed with a screen to prevent critter from burrowing down to the plenum just add a couple peices of LR some macros add a light puff, you got a exporting pod cultivating refugium FYI. most public aquriums employ a plenum. __________________ "He who sees things grow from their beginnings shall have the finest view of them" ........Aristotle........ "The only difference between me and a madman is that I'm not mad." - Salvador Dali my chronicle........ http://www.reefsanctuary.com/forums/...al-system.html

09-23-2007, 08:44 PM	#12 (permalink)
Scuba Steve Bryozoan Join Date: Apr 2004 Location: Sebastopol Posts: 40 View Gallery Karma Komment Add yours!	Re: Plenum versus Refugium Does it need to be a particular type of light? And does the sand bed need to be a certain depth?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)