I'll give one other voice to this thread (just so you know where I'm coming from, I have NO experience with DSB/Plenums)...

I still think wet/dry's are great for fish only systems.  Water changes do a fine job at keeping nitrates in check.  A DSB may help too, but I don't think you should disregard the capacity of a good wet/dry.

I personally don't feel that bioballs (wet/drys) are needed in a well stocked reef aquarium.  I'm of the school of thought that zero nitrates is a good target to shoot for.  A friend of mine had a reef 10 - 15 ppm nitrates and a filter mat in the sump.  Within a month of removing the mat the nitrates dropped to below 5 ppm.  The mat was used for mechanical filtration, but was not changed out often enough and ended up being more of a biological filter.  Maybe the same results could have been obtained by changing the mat more frequently, but he didn't want to go this route.  The tank was well skimmed.  I think the skimmer removing the dom is important.  The way I see it, the live rock is very porous and conductive to denitrification (same idea as DSB) Maybe the results had nothing to do with any of this and some other force is at work...

Quote: Originally posted by Mark Peterson on 17 March 2003

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One more comment and then I'll get off my soap box:

 In actuality, the best mode of filtration for both is the sand bed which allows for conversion of nitrates to gas and water. Any other equipment or method is a poor substitute for natures way.

Mark

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Becareful with statements like this Mark.  I know your feelings, but saying that this is "nature's way" is misleading.  Many people could argue that the reefs are not clean and are not converting nitrates. 

Others would argue that a protein skimmer is the most natural method.  And even bioballs are questionable.  They certainly do work (almost work too well), they just don't do everything you want them to.  I would say they are a great addition to a filtration system.

I'm sure more discussion will follow....

Adam

One more comment and then I'll get off my soap box:

Traditionally the literature and pet stores saw a diference between optimum filtration for a fish-only and a reef set up. In actuality, the best mode of filtration for both is the sand bed which allows for conversion of nitrates to gas and water. Any other equipment or method is a poor substitute for natures way.

The old school of thought is that a wet-dry is best for fish, but that's a fallacy because it does nothing for nitrates. Of course, higher nitrate levels are not a problem for fish, but why use only 2/3 the filtration. The lack of that other third does cause problems. Yes, there are very nice aquariums using wet-dry (waiting for a bioball crash), but my opinion is that the very best is the more complete biological system.

Mark

With regards to bioload, it's evident that mechanical filtration will increase the limits of the bioload by removing detritus. But when biological filtration (DSB, RDP refugia, etc.) is used, the aquarium nudges closer to a natural environment which, by the way, is more artificial than wild!

my 2 cents

Tried it and discarded it as unecessary in favor of sand on the bottom and have found that Utah Oolitic works great without the need for a ton of sand on the bottom.

Please read previous posts in this forum (undergravel filter, aragonite, DSB, etc.) to discover that most people have discovered that the plenum is not necessary. Also, Jaubert had a direct water exchange with the Mediterranian (spelling?) ocean so his success was not so much due to his plenums as to other features of his set-up.

Mark         "thinking outside the box"

I have been thinking about setting up a tank (primarily fish) using the jaubert method.  Has anyone tried this method?  If so what kind of experience did you have?  Did you add supplements?  Must you maintain a lighter bio-load than with mechanical filtration?  Any info would be extremely helpful.  I am using a 75 gallon tank.

Thanks

rob