Plenum
Printed From: Utah Reefs
Category: Specialized Discussion
Forum Name: DIY
Forum Description: Do it Yourself
URL: http://www.utahreefs.com/forum/forum_posts.asp?TID=36050
Printed Date: July 16 2026 at 12:27am
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com
Topic: Plenum
Posted By: blasterjr
Subject: Plenum
Date Posted: October 27 2009 at 6:20pm
|
What are the pros and cons of a plenum? How do they work? Do you use a sump to draw the water down through the sand? i have seen some threads on the forum on how to set them up. I am an experienced hobbiest with fresh water and I want to set up my first reef tank. I am planning on using a 55 gal. I am trying to find the least expensive way to filter the tank. Please help me out. Thank you in advance!
Bryce
|
Replies:
Posted By: Jeffs_little_ocean
Date Posted: October 27 2009 at 8:18pm
| In my clueless opinion I would say the best way to filter the tank is with alot of live rock and good flow throughout the tank. The next best thing is a good skimmer. Im starting to learn that in salt water, the term "least expensive" can come back to bite you. You usually get what you pay for. |
Posted By: CapnMorgan
Date Posted: October 27 2009 at 8:53pm
|
I can't really say there are any cons to having a plenum. But you really don't need one IMO. But it never hurts to have one. But with plenty of LR, a good refugium w/ a deep sand bed and lots of macro will keep nitrates well under control. Also you can add some fine sand underneath the coarser sand in the display to grow anaerobic bacteria. ------------- Steve http://utahreefs.com/forum/forum_posts.asp?TID=40637&PID=356246" rel="nofollow - My Old 180G Mixed Reef Currently: 120G Wavefront Mixed 29G Seahorse & Softies Running ReefAngel Plus x2 435-8 |
Posted By: MadReefer
Date Posted: October 27 2009 at 9:07pm
| My understanding is that a plenum just makes a deep sand bed work a touch better. Not worth the space in my opinion, unless you have a tall tank. |
Posted By: Corey Price
Date Posted: October 27 2009 at 9:13pm
| Just do a search for DSB and plenums and set the criteria to "any date". There are gobs of threads on it. One thread was five or six pages long and had a heated debate. |
Posted By: Mark Peterson
Date Posted: October 28 2009 at 8:31am
|
Hello Bryce. Welcome to the worlds best and most reliable source for reefkeeping information; welcome to the WMAS.
I was in freshwater for many years and have had both fresh and saltwater tanks for most of my life. I started in the reefkeeping hobby in 1993 with an undergravel filter that I soon turned into a plenum. Over the years I have used them again along with other methods of filtration. I have found that a bed of Oolitic sand right on the bottom works the same as a 4-6" plenum. I make it 1-2" deep in front and on the sides, sloped up to 3-4" in the center back. The difference is appearance. If you like looking at the side of a bunch of sand then do a plenum. If you want to see coral and fish on a white sandy beach, do the Oolitic sand. Add portions of larger particle sand or even rubble in some areas to add variety and natural reality to the look.
Here is a link regarding setting up an affordable and beautiful reef aquarium:
http://www.utahreefs.com/forum/forum_posts.asp?TID=9244 - http://www.utahreefs.com/forum/forum_posts.asp?TID=9244
In that thread there are links to a ton of other useful information that will help you get started. Feel free to call me at the number below. ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member 
|
Posted By: blasterjr
Date Posted: October 28 2009 at 9:58am
Thanks for the imput. Now for a new question... This is some rock that I had in a fresh water aquarium is this ok to use a base rock?
 |
Posted By: Jeffs_little_ocean
Date Posted: October 28 2009 at 10:29am
| When I switched over from fresh to salt, I got about 75 lbs of LR from someone who was getting out. It was beautiful rock covered in coraline and full of pods and life. I put it in my tank and decided to add afew pieces of the rock from my old freshwater tank. They looked similar to the rock you posted. Lavarock I think. After 6 months, the coraline was growing all over everything. Powerheads, overflow, even the magfloat. But those 2 laverocks still looked exactly the same as the day i put them in? I have no idea why, or the chermistry behind it. I eventualy took them out and threw them away. |
Posted By: dduts
Date Posted: October 28 2009 at 11:31am
|
Hi Bryce
My recommendation is to not use your old rock unless you know for certain that it doesn't have any copper or other metals in it. You'll have a rough go at saltwater if it does contain metals. Just pick some up from a member or go gather some out by Stansbury island if you know what you're looking for.
------------- 90g mixed reef GOT CRABS? Sometimes I wonder "why is that frisbee getting bigger?"....and then it hits me |
Posted By: bfessler
Date Posted: October 28 2009 at 9:26pm
|
Here is an interesting article on the effectiveness of plenum's vs DSB. They did controlled side by side tests on many DSB's and Plenum systems and found that the DSB is actually more efficient than a Plenum.
http://www.advancedaquarist.com/2005/6/aafeature - http://www.advancedaquarist.com/2005/6/aafeature
------------- Burt An equal opportunity reefer, I support all hobbyists and organizations involved in Marine Aquarium Keeping. [email protected] |
Posted By: blasterjr
Date Posted: October 28 2009 at 10:15pm
| So If I do a DSB how deep should it be in a 55 gal? |
Posted By: bfessler
Date Posted: October 28 2009 at 10:20pm
|
I put a 4" DSB in my 55 frag tank. It creates tons of life to feed the corals and my Scooter Blenny. I haven't had to feed the guy in over 3 months. Generally I think between 3 and 6" is considered optimum. I like the depth of my tank because I can blow out the top layer with a turkey baster but not upset the lower anaerobic layer. ------------- Burt An equal opportunity reefer, I support all hobbyists and organizations involved in Marine Aquarium Keeping. [email protected] |
Posted By: BobC63
Date Posted: October 28 2009 at 10:25pm
I call "flawed science" on this article!
  ------------- - My Current Tank: 50g Starfire Cube Reef * Marine & Reef tanks since 1977 * |
bfessler wrote:Posted By: bfessler
Date Posted: October 28 2009 at 10:28pm
|
Hi Bob,
Explain Please. It seemed pretty straight forward to me. ------------- Burt An equal opportunity reefer, I support all hobbyists and organizations involved in Marine Aquarium Keeping. [email protected] |
Posted By: BobC63
Date Posted: October 28 2009 at 10:39pm
|
Hey Burt -
Actually, "flawed science" isn't a correct comment.
My problem with the article (the experiment, really) is that it is a short-term experiment.
And yes, a properly set up DSB will nitrify and denitrify just about as well as a properly set up plenum will. On that parameter there really is not much difference at all.
The difference - and IMO, the advantage of the plenum - comes long-term, when a DSB may start to run into problems with excess detritus buildup, sand compaction due to decline in sand-moving infuana within the sandbed, possibility of hydrogen sulfide "pockets" forming in areas where compaction occurs...
All potential problems for a DSB; none of which can occur with a plenum. Why not? Because water motion through the plenum is not performed by living creatures stirring the sandbed, but rather by the infinitely small changes in water temp and density that occur on either side of the plenum itself and that generate a very gradual movement of water into and then out of the plenum void space. (If you have sand - stirring creatures in a plenumed sandbed that's fine; it's just not neccesary like it is with a DSB.)
IMO, a 5 - year experiment, using actual livestock instead of chemicals, might show a more evident difference between the 2 systems.
------------- - My Current Tank: 50g Starfire Cube Reef * Marine & Reef tanks since 1977 * |
Posted By: Mark Peterson
Date Posted: October 28 2009 at 10:42pm
|
I agree. Not a good idea to use that Lava Rock in a Reef Aquarium. Utah Rock is so excellent because it is made up of the same minerals as LR from the ocean, why use anything else for base rock?
 What size of sand do you want? Which do you like for looks? Did you read the thread that I gave above? Studies can be biased in the way they are set up and I know from seeing hundreds of hobbyist tanks that almost any method can work if the hobbyist makes it work. I've heard that if you were to see Bob's tank in comparison to a tank with DSB, you would swear there is no difference in filtration effectiveness between the two methods.  ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member
|
Posted By: bfessler
Date Posted: October 28 2009 at 10:56pm
|
Interesting, I would have to agree with Mark's analysis. Even the article I mentioned said there is really little difference between the two as far as efficiency. When I set up my frag tank I installed a DSB of 4 to 6 inches over a plenum. After reading the article I thought I might have eliminated the plenum.
I love the life that grows in the DSB and the Corals also seem to like it. I try to blow out the top 1" or so weekly which should mitigate any problems with hydrogen sulfide if the plenum was missing. Bottom line if properly maintained many systems will work well. ------------- Burt An equal opportunity reefer, I support all hobbyists and organizations involved in Marine Aquarium Keeping. [email protected] |
Posted By: CapnMorgan
Date Posted: October 28 2009 at 11:32pm
I couldn't agree more. IMO one of the best ways to keep your corals fed is to use the food "naturally" provided by the biological processes in the tank. I stir the top inch or so of about 1/3 of my sand bed once per week. It clouds the water with all sorts of goodies for the corals and other filter feeders like my clam, feather duster, and sponge. But I also have lots of crabs, various snails, a cucumber and conches that sift the rest of the sand bed for me. The greatest things about reefing is there are lots of right ways to do pretty much everything. It all comes down to which method(s) provide the best results for you. ------------- Steve http://utahreefs.com/forum/forum_posts.asp?TID=40637&PID=356246" rel="nofollow - My Old 180G Mixed Reef Currently: 120G Wavefront Mixed 29G Seahorse & Softies Running ReefAngel Plus x2 435-8 |
Posted By: blasterjr
Date Posted: October 29 2009 at 11:03am
|
I read through other thread links that I was given. It was great infromation. my next question is about refugium. I have seen pics and vids of retugium. What is in them and Where do I get some? (The green plant looking stuff) my tank is drilled so i am planning on useing a refugium.
Any input is great.
Is there any on in the Bluffdale Riverton Herriman or South Jordan Area that would help take me under there fin <wink> pardon the pun.
I would like to look at some peoples set-ups
|
Posted By: bfessler
Date Posted: October 29 2009 at 11:55am
|
Refugiums are an excellent addition to your reef. They provide lots of natural live food for corals and fish in addition to nutrient export. They can be installed as part of the sump or stand alone. The refugium should be placed after the skimmer and mechanical filtration and just before the return pump. There are many things that you can place in the refugium but they are most often stocked with Macro Algae, Live Rock and a Deep Sand Bed.
The live rock and DSB provide the same benefit as using it in the display and are frequently used when the look of a shallow sand bed is desired in the display. Another benefit is the pods and critters that grow in your refugium are not constantly hunted by the fish and inverts in the display so their populations can grow larger than if in the display.
The macro algae will remove nitrates and other nutrients from the water column decreasing the amount of algae that will grow in the display and keeping your water quality up. Usually the refugium is lit on an opposite schedule of the tank to keep oxygen levels up in the display during the night hours.
Occasionally stirring the algae and sand will release the natural foods into the water column and be pumped to the display to feed fish and corals. ------------- Burt An equal opportunity reefer, I support all hobbyists and organizations involved in Marine Aquarium Keeping. [email protected] |
Posted By: blasterjr
Date Posted: October 29 2009 at 2:05pm
|
I'm going to start a new thread in the filtration for my refugium questions |
Posted By: paleohead
Date Posted: October 31 2009 at 11:35am
|
I used to hear that a plenum was just a time bomb of nasties waiting to explode! So the logical thing for me was to do my water changes out of the plenum. I used airline tubing and plastic tees to make a network of drains in the plenum. When I needed to do a water change, I opened a small valve and did a slow water change. Never had a problem. Did a check on the water I removed from my plenum. The plenum does act as a sort of a sink for nasties. It does it's job. ------------- Collecting for the public to see! |