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GARF's "Bulletproof Reefs" (1 Viewer)

I believe Grigor made his 300 gallon tank this way. Seems like a great idea if you are doing an in-wall where you only need 1 viewable side
 
One thing I noticed is it looks like they still recommend using sea chem's reef calcium, and I don't know of anyone on here that would recommend using that stuff.
 
4 months is nothin'. I went skimmerless on a 180g sps dominate for about 18months before I ran into trouble.

Plenum has been talked about many moons ago. What good is a blank space if there is no surface area for bacteria etc. to colonize ?

In the end, they just want you to buy there grunze stuff.
 
David Grigor said:
...What good is a blank space if there is no surface area for bacteria etc. to colonize ?...
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It was best explained to me like this:

-Take a sponge and set it in the sink under a running faucet. The majority of the water will bounce off of the sponge because it'll pretty much get backed up because of resting directly on the sink. (water hits sink bottom, has to [slowly] flow out the sides, and gets backed up)

-Now suspend the sponge so it's not directly supported by the sink. The water will flow through it because of this blank space below the sponge.

What I get out of that analogy is that the blank space provides the water with the opportunity to flow through the substrate/plenum as opposed to just getting backed up. I've also noticed this while in the entry way of a building. When both doors are open, air flows through, however if either one of the doors is closed, everything stops, and the air in the entryway doesn't move, despite the open door because, once again, it's backed up
 
:beerchug:
hamdogg08 said:
It was best explained to me like this:

-Take a sponge and set it in the sink under a running faucet. The majority of the water will bounce off of the sponge because it'll pretty much get backed up because of resting directly on the sink. (water hits sink bottom, has to [slowly] flow out the sides, and gets backed up)

-Now suspend the sponge so it's not directly supported by the sink. The water will flow through it because of this blank space below the sponge.

What I get out of that analogy is that the blank space provides the water with the opportunity to flow through the substrate/plenum as opposed to just getting backed up. I've also noticed this while in the entry way of a building. When both doors are open, air flows through, however if either one of the doors is closed, everything stops, and the air in the entryway doesn't move, despite the open door because, once again, it's backed up
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You're hoping for bacteria growth, no? What are the filtering qualities of the water in the plenum? It's a waste of space IMO...:beerchug:
 
Sometime this weekend, I'll transcribe what I read in a book about why there's an empty spot in the plenum. Until then, I'll be recovering from working midnight to 8
x_x
 
After the space... there is glass. imagin and entry way with one set of doors closed.
Its not to say some interesting observations have been made, but the bennifits or even just the uniquness haven't warented the continuation of this method over a DSB.
 
Using a plenum is very different than a DSB.... With a plenum, the water never goes anoxic, there is always a little oxygen even at the lowest levels. This is all the plenum does, it is not a place for bacteria to grow (though I'm sure it is). A DSB, it does go anoxic, hydrogen sulfide will develop. Usually this is not an issue.

What is different also is that if you look at how Dr Jaubert describe his system, there is little live rock in the tanks, and much of it is on the back wall. When Delbeek did the 3 year study on plenum systems at the Waikiki, there was a lot of live rock on the sand. Jaunbert also recommends courser grained sand and not sugar-sized sand (as in DSBs).

The systems in Monacco, have been up longer than most closed systems 10+ years... there have been some rumours of a crash, but I've found nothing, even on french reef aquaria (I speak french) boards...

I ran a SPS only Jaubert plenum for many years after reading the sea scope article in the 90s, and had no measurable nitrates and phosphates, tested on hach equipment (much better than salifert ****)... it works....

Back to Garf... I like their slow go approach, but I'm not so sure that its completely warranted. If you are patient, go for it. I don't think it should be thought of as some miracle method though. The really nice thing about their approach is that they seek to use nothing taken from the reef.

Edit: I guess I would add that this process works via a plenum due to diffusion. Essentially, once the sand bed is mature, you have an area (which you DO NOT siphon/clean) with a low concentration of nutrients below an area of higher relative nutrients... This is why you want to have a lot of the sand exposed, otherwise, you are limiting your whole reason of putting a plenum in :)
 
I think most people have read about and understand plenums. IMO it's just not a method worth doing. You don't get anything "extra" by having one over other methods, besides losing area in your tank.
 
Anyone notice Garf is "frag" spelled backwards? And it might not have been intentional. I think Garf has been around longer than the term "frag"!
 
morty said:
Anyone notice Garf is "frag" spelled backwards? And it might not have been intentional. I think Garf has been around longer than the term "frag"!
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Never even thought of that?!?

I think that's the only downside....losing 4" on the bottom of your tank. Though if you have a tank deeper than 24", that may be a benefit. What's funny about this whole plenum discussion is that many are using vodka or some form of organic carbon to reduce nutrients.... A plenum is simpler, equally effective and less 'risky'.
 
cwk132 said:
Does anyone have any pictures or diagrams or can even explain what a plenum is to me? Is it a DSB or what?
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This a fairly crude picture of one:
http://www.geocities.com/capecanaveral/hangar/6279/ArticleHandy.html

It essentially a DSB placed on top of a screen, with a layer of non-circulating water underneath it.

Chunks of PVC pipe sit on the bottom of the tank, then eggcrate is placed on top of them. Then a layer of screen goes over the eggcrate, larger-grain sand is poured over it, then another layer of screen, then fine sand on top of that.

This is another article (note the date):
http://www.advancedaquarist.com/issues/sept2002/feature.htm

People have mostly moved away from using them, and rely on today's improved skimmers to take stuff out before it breaks down to nitrate. Reefers also learned that simple DSBs work basically the same as a plenum system.

A speaker at IMAC said that instead of having a DSB in the display, filling a couple ice cream pails with fine sand, placing them in your sump, and seeding them with sand bed critters make good denitrifyers that can be easily removed if problems arise.
 
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