Limitations of DSB's

[Green Chromis]

Jerel, is the reef sand there being constantlly shifted by storms and currents which would account for the lack of food?

[Spanky]

Now if I could just train all those massive schools of porgy's and grunts to hang out somewhere else all day, I could get that reef back on track.

Edit: for those that don't understand that. Porgy's and grunts form massive schools during the day and hang out on reefs. They are the prime nutrient importers to the reef. At night they leave the reef (some times for miles) and forage in the grass and sand flats. Then come back to the reef in the morning and hang out on the reef and poop all day. The detritus builds up in the pockets and caves of the reef and leaks out.
Talk to me about detritus leaking out!

[Spanky]

There's a little bit of that going on Jay. Primarily though, there's just no food there for anything to eat. It's swept away with the current.
The higher relief and structure and porosity of the reef itself traps it. Just the structure of the reef allows it to settle there.
Sort of like live rock in the sump.

[Green Chromis]

Jerel, the detritus and food that absorbed into the reef itself, how is it exported from the reef so it dosn't accumulate like it would in our tanks, I know bacteria take care of a lot of it, but does it take care of all of it or is it passed through the reefs into the bottom media below the reef, or am I missing something ?

[tdwyatt]

Originally posted by NewReefer
WHat is starboard?

opposite of port


...whilst facing the bow I point out the stars with my right hand with a good stout port in my left...

[tdwyatt]

Originally posted by Spanky
Nothing but snow white clean sand. Of course every wrasse in the entire neighborhood was there to see what I was doing...

I guess I will have to take some pix now...

I dug out about 4 inches of substrate with a cup in the 6 y/o sandbed in Wellford today... I am seeing some reduction in the amount of small silts, etc, but I am not seeing the crap/detritus that everyone else is talking about in their sand beds. My original intent was to get about 10 lbs of sand to seed the new tank, but after reading Jerel's post, I realized that although there was SOME silt coming up from the DSB, the remaining sands where absolutely white. I will be taking pix and doing some photomicrographs of the stuff I am taking out as well.

Interesting that this closed system with regular water changes and all the substrate critters, several holothurians, ministars, many Lysmata wurdermanii, several spp of grazing snails, fighting conchs, Diadema urchins, Mesophilia urchins, 4 years of wrasse aggravation, 5 years of a pair of mandarins, 5&1/2 years of grazing by a sailfin tang, never treated with any "quick fixes" and regular 10% WC with IO, low bioload and light feeding has maintained its appearance. and doesn't support the green nuisance algae.

Go figure, I've always swapped sands with folks whenever possible, the corals thrive (MH and VHO lighting), and only nuisance I've had has been the anemonia cf majano that I cannot get rid of. Up until the extended power outage due to the ice this past winter, I never had problems with cyano either (although I see an occasional patch every now and then since then). This is by no means proof that the DSB's work, just my experience, and reading more info about the closed system experiences/studies in the literature may give me a better database from which to work. I am convinced that there are mechanisms that we have been overlooking in the big picture (heck, I am finding out more every day about what a crock some Sand bed secret" keepers have been brewing...) that have their basis of operation based on sandbeds in the oceans as documented in the literature. The suggestion that sand in any location is the same and will have the same characteristics, infauna, trophic relations and dynamic energy relations would not bear scrutiny.

Heck, this is turning into a huge undertaking on my part, there is so much that helps AND conflicts with what I have always taken for granted. I will be posting some abstracts as I begin to put more stuff together.

BTW, Jerel, now that I have more input from some "standard" models" for the trophic energies utilization numbers from the literature, I can see a close to 1:1 production ratio for primary production to trophic consumption, esecially in lagoonal conditions where even with wind driven exchange rates for open ocean water, 100% turnover of the water there may take as long as a year based on the models developed to predict this info.

So many biotopes, so much info, so many variables...



more later, btw, get these NOAA folks to give it up...

[Spanky]

Originally posted by Green Chromis
Jerel, the detritus and food that absorbed into the reef itself, how is it exported from the reef so it dosn't accumulate like it would in our tanks, I know bacteria take care of a lot of it, but does it take care of all of it or is it passed through the reefs into the bottom media below the reef, or am I missing something ?

Massive water changes. LOL

[Spanky]

Originally posted by tdwyatt
opposite of port


...whilst facing the bow I point out the stars with my right hand with a good stout port in my left...

[NewReefer]

all that beautiful sand and nothing to show for it!

To think I've wasted so much dough on pretty sand. Light bio load may be nice but what about the people that tend to get just one more fish? How does that affect the DSB? If I'm reading it right there isn't any nutrients locally on the reef but yet the life supported is thriving, how so, what are they eating and pooping that we can replicate?

[Spanky]

http://www.aoml.noaa.gov/general/lib/salt_river22.pdf

Ok, lets start here. I helped Alina put this paper together a few years ago. It's actually modeled after a reef in front of the house.

In order to understand DSB's, you have to understand closed systems. In order to understand closed systems, you have to understand more about nutrient dynamics on reefs.

[Green Chromis]

Jerel, can we really duplcate or come close to the nutrient dynamics or export in our closed systems compared to that on a reef without massive water changes or an open system and can you duplicate or come close to the percentage of flora and fauna in a DSB or plenum compared to the reef?

[Spanky]

Hummmm

I would think of it more like engineering the environment to maintain parameters within acceptable ranges of the animals you're trying to keep.

That way you know you have several ways of achieving that goal.

[tdwyatt]

Originally posted by Spanky
http://www.aoml.noaa.gov/general/lib/salt_river22.pdf... I helped Alina put this paper together a few years ago. It's actually modeled after a reef in front of the house....

NOW we're getting somewhere!!! I was beginning to believe that NOAA was the "black hole" of reef research, everything goes in, but nothing comes out except xrays...

Thanks Jerel!!!

[tdwyatt]

Sooo Brooke...


What happens when the number of views of this thread gets to 10,000??? I notice the format is only for 4 figures...












whooda thunk that this thread would have gone to 10K views???

[BuckWheat]

If the post goes over 10,000 it restes down to 0 LOL!
Or maybe we should start a new discussion about that!