advice on deep sand bed in sump

[d.french]

i just got everything transferred from 29 gallon to 75 gallon last night and i have 2 2 liter jugs of live sand left and still wet for now do deep sandbeds in fuge area of sump help out at all or should i just keep calurpra and chaeto in sump only.

[capncapo]

Toss the sand or give it away.

Remote DSBs don't work well as DSBs.

They may work as a nutrient sink but if used in that manner you'll end up throwing it out in the future.

[d.french]

thanks capn kinda thought same thing but wanted to make sure before i tossed it or gave it away.

[scbadiver]

Interesting, What is the difference where it is located in the system? I thought it performed the same as long as it was adequately sized? Am I going to hurt myself by making one in the 55 gallon fuge I have? I was going to put about a 5 inch deep sand bed in there.

[sirreal63]

The only issue with a dsb is that it not be disturbed, whether it is remote in the fuge, remote in a bucket or in the main tank. The bucket method is good for being able to take it offline easily. If your fuge doesn't get distrubed, (sand disturbed) then it will work. If the sand gets disturbed too much it will release nutrients into the water column.

[breutus]

I have a 6 or 7 inch DSB in my 30 gallon sump... my thoughts go both ways kinda... It is damn near impossible to clean but at least the sand doesn't get disturbed. I can't say as though I notice much lower nitrates in the tank since its addition 5 months ago. I kind of wish I had not put it in there and it will probably go when I redesign the sump.

[scbadiver]

Hmmm, ok. By disturbed you mean manually right? Not critters and stuff crawling around, hermits, cucumbers etc.? I'm wanting to hook this up this weekend so this is a timely thread for me. If there is a better way I'm open to it. I'd only be in there to trim excess macro growth. So, I'm better off with or without it? Thanks guys.

[sirreal63]

It can go either way Robbie...some love them some hate them. Their are certain mechanics to having one function properly such as sand grain size, microfauna population and surface area. It isn't as simple as piling sand up. There is an article on dsb's that is a good read. I have it saved but not on this pc. I believe it is in the faq's on the main page of RC.

[Nanook]

I think CapnGeritol has the DSB Scrolls memorized...they were originally on papyrus.

[capncapo]

Originally posted by Nanook
I think CapnGeritol has the DSB Scrolls memorized...they were originally on papyrus.

You bet your bippie!

If you believe in what Ron Shimek says ( and I do when it comes to DSBs ) remote DSBs don't get fed like is necessary for a DSB to thrive. You could fee the remote DSB but the purpose of a DSB is to eat the extras that fall to the bottom of the tank. Kind of a moot point at that point.

[scbadiver]

I believe you are right Nook! The old man is the one that talked me into DSB's in the first place, then the forgetfull ol' guy says "don't do it." I guess I just have to wait for him to have one of his lucid moments to clarify all this for us. Maybe when he gets up from his afternoon nap...Zzzzz.

[d.french]

i have deep sandbed in my 125 gallon and it works good for that tank but because there are so many bristle worms and spaghetti worms that overfeeding isn't a problem cause whatever hits sand bed will be gone shortly. So i see how it works better for display tank cause mine is full of life.

[d.french]

i also have 4 sandsifting cucumbers, and a sandsifting gobie that works over sandbed allday to keep it clean.

[scbadiver]

Man, he beat me to the button! Darn work interfering with my real work here at RC.

[breutus]

Yes I mean manually or with to much flow right on it.

THere are some critters in it no cukes but a few snails and then the normal life that inhabits any cheato

[scbadiver]

So, if we believe Shimek and Capo, the remote DSB will not thrive like a "real" one would. Accepted. Will it do more harm? Will it become a nutrient sink and if so, is that neccessarily a bad thing?

[capncapo]

Originally posted by scbadiver
I believe you are right Nook! The old man is the one that talked me into DSB's in the first place, then the forgetfull ol' guy says "don't do it." I guess I just have to wait for him to have one of his lucid moments to clarify all this for us. Maybe when he gets up from his afternoon nap...Zzzzz.

See! That's the problem with you youngsters......you just don't listen!

I won't set up a larger tank without a DSB but I won't ever do a remote DSB.

Anthony Calfo talks about his DSB in a bucket and it may work just fine but is not a DSB in the same sense as the ones that Shimek promotes. It becomes a nutrient sink that will need to be replaced every so often. The type of DSB that Shimek promotes shouldn't need to be replaced because of the critters and bacteria that live in it and help with keeping it clean.

[d.french]

thats for sure at night my sand comes alive with hundreds of spaghetti worms completely covering top of sand bed, tentacles sweeping all over the place.

[capncapo]

Originally posted by scbadiver
So, if we believe Shimek and Capo, the remote DSB will not thrive like a "real" one would. Accepted. Will it do more harm? Will it become a nutrient sink and if so, is that neccessarily a bad thing?

It depends on how you look at it Jack.

If you have to feed a remote DSB ( and by remote DSB I mean one in the sump ) then it will not help with the display because the detritus in the display doesn't make it to the sump....or at least a fair amount of it. The remote DSB is essentially just another bioload at that point. It may help the sump but not the display.

Using a DSB in a bucket may help by being a nutrient sink but isn't what I would consider to be a DSB...or at least not a DSB in the way that they are normally referred to.

[scbadiver]

Ok, I think this is slowed down enough for me to keep up for another minute or two. I did listen to you old man, just didn't let it all soak in. I heard "DSB good, blah blah blah... " .

Now that I addressed that, will my set up help to reduce nitrates in the overall system? And, will it sustain itself from the "stuff" that does make it in from the main display?

I really do appreciate the help here though the more I read the more confused my feeble mind becomes!

[sirreal63]

If you want a dsb to process detrius it will never work correctly, the surface area is too small. Rocks cover too much of the sandbed and the fauna does not move into those areas easily. A shallow sand bed works just as well for processing detrius as a deep one...but with much less danger of nutrients being released into the water column. A dsb works for denitrification from the water column where there are anoxic regions with anaerobic bacteria. This is why the remote sump dsb or in a bucket works (in theory, I am not positive it will make a huge difference) as the bacteria function much like a denitrification coil.

In any event I would not have any sand deeper than a few inches where it can be disturbed as this is where the danger is...releasing nutrients into the water column. My first tank crash came from this happening. An established dsb and an engineer goby is not a good idea.

[scbadiver]

Thanks Jack. I think I'm going to go ahead and put the DSB in the 55 'fuge area and see what happens. It won't be disturbed and if it becomes a problem it can be easily removed in an evening of labor. I re-read Shimeks article and I really do like the benefits described even if I only get small benefit from it. Thanks again guys.

[bprice]

d.french. Thanks for asking the question about using a remote DSB. I am also considering doing the same thing and I found the practical discussion after your posting to be very informative.

[Reeferhead]

Originally posted by sirreal63
If you want a dsb to process detritus it will never work correctly, the surface area is too small. Rocks cover too much of the sandbed and the fauna does not move into those areas easily. A shallow sand bed works just as well for processing detritus as a deep one...but with much less danger of nutrients being released into the water column. A dsb works for denitrification from the water column where there are anoxic regions with anaerobic bacteria. This is why the remote sump dsb or in a bucket works (in theory, I am not positive it will make a huge difference) as the bacteria function much like a denitrification coil.

In any event I would not have any sand deeper than a few inches where it can be disturbed as this is where the danger is...releasing nutrients into the water column. My first tank crash came from this happening. An established dsb and an engineer goby is not a good idea.

I second what sirreal said,

There is simply no biological way to adequately process detritus in our tanks. In nature, the end result is mineralization... not going to happen in our reefs. The only option is physical removal: skimming, filter socks, siphoning. DSB critters are just a life cycle away from becoming detritus themselves, they don't actually remove anything.

However DSBs do work well for denitrification, whether in the tank or remotely, it does't matter where because NO3 is held in the water column. DSBs are also much easier to setup and maintain when your using them strictly for denitrification. There is no need to worry about critters or varying grain sizes. You just need a fine grain sand (I just use silica because it cheap and won't "cement" up) at a depth adequate enough to produce an anaerobic zone at the bottom.

Eventually, a DSB like this will "fill up" and begin to leach nutrients primarily phosphate back into the system. The secondary function of the DSB is to work as a nutrient sink, as it fills up with detritus and traps organics and other nutrients, however, IMO this is not a helpful tool. In order to prevent a DSB from "filling up" as quickly you need to create a swift unidirectional laminar flow across the surface of the sand to prevent detritus from settling and working its way into the DSB. This is where remote DSBs have their advantage because you can easily control the flow regime. Still, most people setup remote DSBs the same way they set them up in their main tanks so they "fill up" just as fast. In the main tank most of us shoot for broad random flow. This combined with all the LR will always create pockets and traps for detritus to settle.

Currently, I don't have any DSBs in my system. I removed the DSB compartments I had in my sump to make room for a larger in-sump skimmer. My bioload is small and I feel I have enough LR to handle the denitrification, plus by removing organics the upgraded skimmer gives me less nitrate to start with. However, when I piece together my dream tank in a couple years, I will utilize remote DSBs for denitrification. I plan on daisy chaining 3 or 4 together so that I can rotate replacing the sand in one about every few months. The water on the surface of the sand will only be about 1" in depth. I will likely use some sort of spray bar to create a swift uniform unidirectional flow across the entire surface of the sand and spill over full length overflow on the other side. this will basically "sweep" the sand surface and prevent detritus build up.

If your looking for super clean water (keeping solely SPS) I think bare bottom tanks are the way to go. Personally I can't stand the look so I keep about 1/2"