Can someone tell me again why we don't like DSBs?

[Regal]

Okay, if talking about detritus that will settle on the DSB, they why we dont put a power head, connect the ouput of power head with small pvc tubing and make a straight small hole along the pvc so the water will come out the hole and blow the detritus on the surface DSB. By doing this the substrate will always clean of detritus before the detritus sink. Is there any opinion about this ?

[elegance coral]

Originally Posted by saf1

Thread hijack. I forget when or how long ago or by whom if truth be told but they lead me to believe they are logoon type creatures. Thus my dirtier water than say what stone type coral would live in.

At the same time if I recall I was keeping a Kole Tang. They also gave me a piece of advise that I'll never forget. Leave one side of my tank alone with whatever algae would grow because the Kole would have a natural source of food...

Oh well. Do you feed yours? Mine would catch and eat whatever floated by but really loved the silver sides. I had a pair of true percs that would actually take it pieces and they lived in my Frogspawn!

There are probably as many myths about Elegance corals as there are sand beds. Yes, they can be found in "lagoonal" type environments. They do much better in the clean environments of coral reefs. Yes, I feed mine all kinds of stuff. Even live feeder fish from time to time.

Now back to your regularly scheduled programing.

[gman0526]

Originally Posted by Regal

Okay, if talking about detritus that will settle on the DSB, they why we dont put a power head, connect the ouput of power head with small pvc tubing and make a straight small hole along the pvc so the water will come out the hole and blow the detritus on the surface DSB. By doing this the substrate will always clean of detritus before the detritus sink. Is there any opinion about this ?

How will you feed the pods, worms and such microfauna that make the sandbed work in the first place? Might as well do what you're proposing and lay down a SSB just for decorative purposes much like LOJ was trying to show, not a DSB.

[LobsterOfJustice]

What do those detritus eaters do to make the dsb "work"? Bacteria denitrify, not pods/worms.

[jenglish]

Originally Posted by Regal

Okay, if talking about detritus that will settle on the DSB, they why we dont put a power head, connect the ouput of power head with small pvc tubing and make a straight small hole along the pvc so the water will come out the hole and blow the detritus on the surface DSB. By doing this the substrate will always clean of detritus before the detritus sink. Is there any opinion about this ?

This is essentially a spray bar. Some folks with rock lifts do use these to keep detritus from settling... it is not 100% though.

Originally Posted by gman0526

How will you feed the pods, worms and such microfauna that make the sandbed work in the first place? Might as well do what you're proposing and lay down a SSB just for decorative purposes much like LOJ was trying to show, not a DSB.

If you are worried about feeding the sandbed you are sort of going about this backwards. It is always better to have poo skimmed out than relying on binding or even denitrification.

Originally Posted by LobsterOfJustice

What do those detritus eaters do to make the dsb "work"? Bacteria denitrify, not pods/worms.

Pods and worms do have a place in a DSB, despite the fact they are still pooping themselves. Critters in your DSB do a number of things: Temporarily binding in biomass, breaking down larger poop into smaller poop, and moving things deeper into the DSB faster than simple diffusion processes can. I do not worry about "feeding them" as there is plenty to eat in most systems and they are largely a carrying capacity regulated population.

[gman0526]

Originally Posted by LobsterOfJustice

What do those detritus eaters do to make the dsb "work"? Bacteria denitrify, not pods/worms.

Absolutely nothing, you know that, I know that, some people don't and they go out and buy "sandbed recharging kits" every now and then.

If you are worried about feeding the sandbed you are sort of going about this backwards. It is always better to have poo skimmed out than relying on binding or even denitrification.
Quote:

Believe you me I know, but since it's so "important" for some people to have a "Dr. Shimek SB" they need to take into account the quantity of pods/worms/microfauna per square inch and those little buggers do eat you know?

DSB's are nothing but a biowaste sink that will eventually (short/long term) fill out there's no way around it.. unless nothing settles there to begin with.

[elegance coral]

Originally Posted by gman0526

Absolutely nothing, you know that, I know that, some people don't and they go out and buy "sandbed recharging kits" every now and then.

There are people that get it. I was beginning to have my doubts.

Believe you me I know, but since it's so "important" for some people to have a "Dr. Shimek SB" they need to take into account the quantity of pods/worms/microfauna per square inch and those little buggers do eat you know?

And his system is still one big cesspool.

DSB's are nothing but a biowaste sink that will eventually (short/long term) fill out there's no way around it.. unless nothing settles there to begin with.

I agree with everything you've said, but this. There is a way around it. Just syphon the sand with a gravel vac. If you keep it clean from day one, it doesn't build up problem causing biowaste.

[jenglish]

Originally Posted by gman0526

Absolutely nothing, you know that, I know that, some people don't and they go out and buy "sandbed recharging kits" every now and then.

I wouldn't go so far as to say they do nothing. They do improve functionality of transport and some other benefits I mentioned earlier. But they are not the drivers of a DSB, that is functional anaerobic bacteria. I honestly don't think you could keep the critters out of a tank if you use any LR at all. I have in the past bought "detritovore kits" and I don't believe there was anymore life in those sand beds than the ones that just started dry sand with some decent LR tossed on them.

[Paul B]

I disagree with everyone about everything.
OK not really, I just wanted to read this thread and I figured after all that reading I would say something.
OK never mind.

[elegance coral]

Originally Posted by Paul B

I disagree with everyone about everything.
OK not really, I just wanted to read this thread and I figured after all that reading I would say something.
OK never mind.

[cloak]

Check out the muck. Perfect!

[Big E]

Shimek "no touch" DSB's work as--

1. Nitrate reducer
2. Home for sand dwellling creatures/fish
3. Looks- make the tank look natural compared to the BB look

That's all they offer in my opinion. There are many ways to meet the 3 needs above. The question is do you want to deal with a DSB's shortcomings for this, or find a myriad of other ways to fill those needs without a "no touch" DSB?

They make it harder to reduce or control PO4 & that's where the biggest problem lies. If you don't vacum the bed, or have high flow to get the junk out before the bed takes it in, PO4 becomes an ever rising problem.

Something has to be done.........macro algae, PO4 removers, vodka/skimmers are fighting with the DSB for control of that PO4 producing waste. If the DSB wins you get algae/cyno problems in the display, some species of corals suffer, & the tank looks ugly.

Imo, pods/worms/critters are useless from a filtering standpoint..........they are just more bioload. If you don't have a lot of waste the critter population will be low. Lots of waste=lot of critters.

These critters are below & at the surface of the sandbed. They poop & the DSB sequesters that poop. If the critters get the decaying food/waste before the flow can pull it out you're screwed from a PO4 perspective. The dentrfying bacteria degases the nitrate, but there is no bacteria in the bed to get rid of the phosphate producing waste........ it stays there......gravity sucks.

I have no desire to argue or defend my points. Just offering my perspective based from personal experience, logical thinking, & what scientific facts I can understand.

[Frogmanx82]

So how deep should a sand bed be if you want to have a home for worms and nassarius snails and microbes that support a healthy pod population? I would think something in the order of 2 inches. Is 3 inches too deep. Thats what I have now. I could siphon some sand out, I'm thinking about it.

[Mike O'Brien]

It's like a lot of these new drugs coming out lately. Sure there are a few benefits but the side effects can be worse than the original problem. LOL

[mukymuk]

I think both, the pro and anti DSB camps have some valid points. Some practical and some theoretical.

If you don't vacum the bed, or have high flow to get the junk out before the bed takes it in, PO4 becomes an ever rising problem.

The basic theoretical rebuttal (and maybe there is even experiential data to support it--I don't know) to this is that in a "good" DSB, there is no "junk" accumulation. Big stuff eats food and poops, certainly, but that's not where it stops. That waste is, in turn, is a food source for others---and so on until you end up with NO3, PO4, and CO2 that dissolves into the water.

I think in practice a lot of folks don't see the entire cycle--something gets broken along the way and some (most?) of the N+P+C, gets locked up in the sediment and remains there until the DSB gets disturbed--vacuuming, powerhead mishap, whatever.

That broken "something", is likely insufficient infauna--be it bacteria or bugs, or whatever. To me, the fundamental problem with DSB's is really in the practical definition of what they are. And by "practical" I mean "easy for the average reefer to understand and replicate".

So a lot of people have tried them, watched them fail for unknown or presumed reasons and just written them off. Fine. There's a lot to be said for practical reefkeeping. But that doesn't mean the idea isn't a good one and can't be made to work well, because the reality is a fair number of people have made the work very well.

So how deep should a sand bed be

DSB's are generally considered to be something at least 3" in depth. I think 6" is the ideal though.