A take on BB methodology.

[Bomber]

Yes, I understand that BBs advantage is that for the most part you get the detritus out before it rots. The biggest thing I'm trying to point out is that you still have sinks in the tank and that your aren't getting everything out, therefore you can't run the tank indefinitely.

What sinks?

 

[AlgaeMan]

I'm trying to point out is that you still have sinks in the tank and that your aren't getting everything out,

Yes there will always be some detritus that will accumilate, but with proper flow it should not be a concern. A BB system with inadequite flow is probably worst than a dsb system.

 

[FastFish720]

Bomber - Is the the buffering capacity of a DSB or SSB w/aragonite make a huge difference in pH and alk in comparison to a BB system?

 

[joefish]

Yes, I understand that BBs advantage is that for the most part you get the detritus out before it rots. The biggest thing I'm trying to point out is that you still have sinks in the tank and that your aren't getting everything out, therefore you can't run the tank indefinitely.

The LR is the sinks you are refering to?

Why would LR back up with nutrients ?

 

[Bomber]

Yes there will always be some detritus that will accumilate, but with proper flow it should not be a concern. A BB system with inadequite flow is probably worst than a dsb system.

Oh, I thought bean was saying since there are some sinks in the tank anyway, you might as well have a HUGE one.

 

[joefish]

Bomber - Is the the buffering capacity of a DSB or SSB w/aragonite make a huge difference in pH and alk in comparison to a BB system?

I'm not bomber but i do know this first hand , the answer is no .

When I went from DSB to BB in one day there was no change in my alk and calcium although I had the same regiment . The PH did go up a little since there was no decay going on .

 

[Bomber]

Bomber - Is the the buffering capacity of a DSB or SSB w/aragonite make a huge difference in pH and alk in comparison to a BB system?

Buffer/Alk is carbon. Bacteria are the primary consumers of carbon. The more dirt you have, the more bacteria you have, the more carbon consumption you have.

The more bacterial flock you remove from the system, the more carbon you remove that's associated with bacterial flock.

 

[FastFish720]

Thanks! Can you say Thread of the Month?

 

[redwinger02]

Jake that was a concern of mine when I switched and it was not a problem at all. My PH stays stable and so does my ca and alk.

 

[FastFish720]

John-Thanks for the quick info, I'm thinking about switching over in the near future.

 

[photobarry]

Our systems have been up and running since the late 50's. Sometimes they are closed, sometimes they get a water change. Open or closed systems really have nothing to do with it. It does not matter if you get detritus out by skimming or siphoning with water changes, as long as you accomplish the same end result.

That's the biggest mindshift that you have to make when going from a DSB system to a BB system. (And why the old hobby BB systems didn't work.) Rapid nutrient export is the primary goal of the contemporary BB system and of marine lab systems. It doesn't matter how this occurs: constant flushing, siphoning or skimming. The DSB and old hobby BB systems rely on nutrient cycling within the tank. (Think back to the large wet-dry filters in old Berlin setups.) Some people are still trapped with the mindset that you have to process everything in the tank; or that if you don't have some of these biological cycles taking place in the tank, that you will fail.

 

[FastFish720]

So what we are realizing is biological filtration is less important than we thought it once to be. Now we are stressing mechanical filtration via filter socks and skimmer etc.

Did Dr. Shimek ever finish his research to determine if porus live rock was able to breakdown nitrate if placed in a low flow area?

 

[redwinger02]

Your rocks take care of the biological filtration.

 

[photobarry]

So what we are realizing is biological filtration is less important than we thought it once to be. Now we are stressing mechanical filtration via filter socks and skimmer etc.

Not necessarily. The only important thing is what happens to organic wastes found in the tank (either from the animals or from feeding and other direct inputs.) If you don't skim or sipon out detritus, then biological filtration is of much importance. But if you can remove a large amount of waste prior to it breaking down, then you can rely much less on biological filtration. In that scenario, you are using the biological filtration system much more efficiently, as opposed to needing much more biological filtration if it had to process all the waste in the tank.

 

[Weatherman]

I just got a chance to read this article:

http://www.advancedaquarist.com/2005/7/aafeature

And I thought this conclusion was interesting (emphasis mine):

Ã"šÃ‚· Overall death rates were roughly twice as high in aquaria with shallow sediments as in deep sediment treatments. The highest overall death rates were seen in aquaria with shallow coarse sediments over a plenum, and the lowest death rates occurred in aquaria with a sandbed composed of deep coarse sediments. The treatments that were closest to the design aquarists employ for deep sandbed, Miracle Mud and Jaubert plenum aquaria had intermediate death rates. The shallow coarse sediment design that is closest to that used in Berlin systems had one of the highest death rates, and the deep coarse sediment design for which there is currently no accepted name had the lowest overall mortality (Fig. 10). We did not test bare bottom tanks, but the data clearly suggest that the shallower the sediment, the higher the mortality rate, and you can't get much shallower than a bare bottom tank!

 

[Mike O'Brien]

We did not test bare bottom tanks, but the data clearly suggest that the shallower the sediment, the higher the mortality rate, and you can't get much shallower than a bare bottom tank!

Sound's like good science there. LMAO

 

[FastFish720]

Yes, but the concept is different. Even with some substrate, I would be uncomfortably with the high amount of flow that I would implement into a BB system.

It also forgot to factor in your level of husbandry and your experience. I Would not recommend a BB system for a newbie. It would be a nightmare.

 

[photobarry]

We did not test bare bottom tanks, but the data clearly suggest that the shallower the sediment, the higher the mortality rate, and you can't get much shallower than a bare bottom tank!

And of course you would expect to see lots of death in a bare tank with no nutrient export and a high level of biomass inside. But that's not terribly relevant to how BB tanks are actually being run.

I could do a similar experiment with tanks of different sediment types and depth with continuously flowing NSW. And I could show that the greater the sand depth, the greater the nutrient accumulation within the tank.

I don't think either study would be a fair representation of reality.

 

[Bomber]

Well that's what sediments do. They trap nutrients.

and the shallower the sand bed, the less the sink, the more the leak, the higher the mortality.

Unless you eliminate the sand all together and don't have a place to store and leak it.

Barry, you work around in the marine labs on the west coast. Does anyone out there use sand for anything other than directly related to sediment studies or benthic ecology?

 

[jackson6745]

Oddly, I have been struggling with RTN/STN in my 5 month old BB system. I checked every aspect that I can think of (cal, alk, mag, po4, no3, PH, stray electrical current) and everything tests normal. I don't have an explanation why I am losing many corals, there are many different reasons why that could be, but in 2 years of running a DSB tank I only lost 1 coral.