Mud Question  11/9/05
Hello Crew.
<Steven>
I have been reading up on the "Miracle Mud" and the benefits from utilizing it. I have a 250 gallon FOWLR along with a 50 gallon sump + refugium set up. In the main tank I have ~225 lbs. of Tonga cured live rock, and about 4-6" live fine aragonite deep sand bed. In the refugium I have crushed live rock with Caulerpa and mini compacts running 24hrs/day.
The inhabitants are a medium Orange shoulder tang, medium/large Longnose Butterfly, large Bicolor Rabbitfish, med/large Bicolor angel, small/med. Chevron, 30" Zebra moray, and a medium Chrysurus angel. 
I was thinking of removing the crushed live rock as the substrate in the refugium and replacing it with miracle mud. Could  this mud be used without the Eco System set up, and instead just added to my already existing refugium section of my sump?
<Yes>
If so would there be a problem with taking the Caulerpa off of the crushed rock, removing all of the rock and replacing it with the mud, then add the Caulerpa back on top of the mud?
<Not likely>
Last question: Would this process potentially shock my system by removing the rock/Caulerpa, then adding the mud and Caulerpa back?
<Mmm, there is a possibility of the Caulerpa "not being happy", but taking care to pinch/crush it off the existing rock, rinsing it before returning in/over the mud/refugium should be fine>
I will stay with the skimmer as I tend to be an "over feeder" and don't entirely buy off on the concept of Miracle Mud to the exclusion of a skimmer. 
Your thoughts are greatly appreciated.
Steven 
<I would use both the Mud and a skimmer... Leng Sy is a friend, oh, and the owner/mgr. of EcoSystem Aquarium... and he has relented re his stance on the use of both. I would leave yours "on" continuously, though some folks advocate, use skimming in conjunction with mud filtration on a punctuated basis (with a timer, on/off every few hours). Bob Fenner>

Mud/DSB/Refugium - 09/30/05
Hello and thanks for the great site and forums.
<<Glad you like 'em.>>
I could not link to the forums page to post there, so I thought I would send an email.  Thanks in advance for your help.
<<Email is fine.>>
I am setting up a built-in system intended to house a live-rock based reef.  My 90G show tank overflows via a custom tank top into a 55G tank converted to a three-chamber sump and returns to the main tank via a pump running at probably 1100gph (Supreme Mag Drive 12).
<<Mmm...pretty good pump...but with head height, probably returning a bit less than you think.>>
This custom setup was originally intended to house an ecosystem (mud) filter in the central chamber (about 20" x 12").  Over time and having read various apparently conflicting information, I wound up investing in some Aragamud from CaribSea instead of Miracle Mud.  Do you know this product, and is it intended to be an alternate to MM or have I been steered in the wrong direction.
<<Honestly, no...I'm not a user/familiar with either product.  Though I think for the application you describe either will suffice.>>
I may be confusing the functions of a DSB with a mud tank with a refugium, and what I really want to do is set it up right in the first place.
<<Either will do what you desire.  The finer grades of substrate just require less depth to get the job done.>>
My goal is to create a system that allows relatively low maintenance - i.e., it provides filtration (denitrification and nutrient export) , it can provide planktonic food, it can reduce the amount of artificially added supplements needed.
<<Oh... so you are seeking Utopia! <G> >>
So is this ideal system a mud tank with just a thin layer of mud and macroalgae, a DSB with live sand live rock rubble and macroalgae, or something else?
<<My preference is a 6" DSB of sugar-fine aragonite with Chaetomorpha algae.  Though you could add a layer of "mud" on top of the DSB if you want.>>
I have read through many of your excellent forums, but am still confused.  Does a mud system accomplish denitrification?
<<If deep enough, yes.>>
Can a mud system support creatures that could produce the planktonic food a "refugium" can?
<<I think a vegetable refugium excels here.>>
Does a DSB have to be "partially changed out" like Ecosystems recommends mud systems do?  
<<Not so much changed out as added to.  Aragonite has a half-life of about 18 mos. so you'll need to add more every so often.>>
Sorry for the disorganized questions.  Your advice is greatly appreciated.  I have already invested $$$ in the system, if I have to invest more to set it up right in the first place, I am ok with that.
<<<<Very good my friend, starting right is key... EricR>>

Re: Mud/DSB/Refugium - 10/01/05
Thank you Eric.
<<Welcome>>
The 55G sump is only a 8" or so lower than the show tank, so there isn't a lot of head loss on the pump.  I designed and had built acrylic parts that allow the water in the 90G to rise above the rim, and literally overflow down a spillway (ramp) into the 55G, so the 55G is right next to and nearly the same level as the show tank.
<<Ah!... Sounds like a very interesting design.  Would imagine this allows you to move much more water (and quietly too!) than a traditional overflow does.>>
In reading your posts that address DSB's, as well as the offerings from IPSF etc., I am again confused as to fauna.  IPSF sells kits that contain sand sifting creatures like ministars, yet I see advice in your forums saying you DON'T want such creatures in your sand.  Can you clarify?
<<The purpose of the refugium is to allow desirable biota to flourish and reproduce...thus...you want to limit/prevent introducing organisms which will feed on this biota...which "sand sifting" stars do VERY efficiently.  But if these are mini-brittle stars, they can be desirable as detritus feeders.>>
And how to prevent H2S problems like I see in at least a couple frantic posts?
<<While it is a possibility, it's not your "destiny" to have H2S problems because you have a DSB.  Good maintenance/husbandry practices and (this is very important)...STRONG water flow will prevent any calamities.  I've kept deep sand beds for years, and still do, with no such (H2S) problems.>>
Once again, thank you!
<<Very welcome, EricR>>