Sand beds and crushed coral substrates

[SnowManSnow]

isnt it basically just a buildup of organics in the dsb that eventually gets too heavy for the nitrification process????

B

 

[Anonymous]

Is there a chance, just maybe, that years ago, people vacuumed the cc too much and took this stuff out? That was what we were "supposed" to do.

Sure, however there was the school that you didn't need to vaccum it as well.

I havent vacuumed in about a year or more, and I noticed that suddenly, a whole ecosystem popped up. The creatures, I surmise, are eliminating this detrius quickly.

How do you know you have little detritus? Have you been stirring up the cc to check?

With more and more about the debate on dsb vs bare bottom vs this and that, and the continual stories of having to switchout sand beds every few years, I am just wondering, do we need to look to a different method, perhaps.

Careful not to generalize those stories. The are people who don't change out their sand, and people who recommend not touching it at all. Further, there are examples of just about every style of reef husbandry working very well and examples of them crashing.

Protein skimmers have helped and werent in wide usage when cc was more popular. Perhaps this one device, coupled with cc, made the difference now?

I don't think so.

 

[Anonymous]

I stopped vacuuming, and I noticed a lot more life top to bottom. My layer is about, geez, guessing a bit here, but about 2-3" or so.

When I see dsb, I notice very little life in the top layers, and none below that. It is dead, or seems most likely to be.

The DSB 'experts' would tell you that that bed is not being kept properly. In my octopus system I have a deep sand/muck bed. Its teeming with life. For the most part, when I had a DSB, it was also teeming.

Bare bottom, would, perhaps have MORE detriss, because you dont have the bristles, the little starfish (please, what is that species of starfish called...they look like tiny brittles?) and all of the other usual suspects that usually live in the LR and can devour it.

This is also the thing that I feel that got DSB's in trouble. The little critters don't make the detritus vanish. Thats not possible. They can break down some of it, but the 10% rule comes into effect very quickly. Even in the wild, the detritus doesn't get consumed, rather it get flushed out of the reef systems to settle in lagoons or the abyssal plain.
In a cc, I wouldn't think that you would have any more or any less detritus than in any other type of system.
In a BB system you do have the bristles and micro stars and all the other usual suspects (maybe not spaghetti worms though). Also, the point of most BB systems is to not allow the detritus to settle at all, but to keep it in suspension so it gets removed by filtration or skimmers.

Dont forget, skimmers now can take care of a lot that usually in the past could not be removed. SO now we have the skimmers taking out the little stuff, and the creatures in the LR and cc taking out the bigger stuff.

I think that is a little off base. The skimmer can only take out what gets to the skimmer. If the detritus is allowed to settle in the tank before it gets to the skimmer, the skimmer cant do anything about it.

And it was prompted by hearing about another tank failure and having to start over. Maybe sand really isnt the way to go for the AVERAGE hobbyist.

I am sure sand can be supported easily by the true, pure hobbyist who is devoted to the hobby, but maybe for people like me, who like the hobby, but dont really have the time or energy tomake it their one hobby, but enjoys it, maybe this cc works long term, easier than sand.

I think its all system dependent. I think in either a sand or cc system you run about the same risks of a crash or not a crash. The myth of the DSB was that you could set it up and not have to do anything to it, and I think believing the same about cc would lead to the same types of problems.

I feel sand only works in the ocean, because of the incredible, unfathomable diversity of life in and around it. But in a closed system, I feel it inevitably dies, by creating a dead zone. It seems more and more that is becoming common.

CC seems to solve this one aspect.

Sand generally doesn't work that way around reef systems. In almost all the wild reefs I have seen, the sand is way below the coral and is pretty much empty of life and is pretty clean. In lagoonal areas you see critters like you do in a DSB - and that sand is full of detritus.

 

[Anonymous]

I stopped vacuuming, and I noticed a lot more life top to bottom. My layer is about, geez, guessing a bit here, but about 2-3" or so.

When I see dsb, I notice very little life in the top layers, and none below that. It is dead, or seems most likely to be.

The DSB 'experts' would tell you that that bed is not being kept properly. In my octopus system I have a deep sand/muck bed. Its teeming with life. For the most part, when I had a DSB, it was also teeming.

My biggest frustration with such experts is their lack of any formal background in biogeochemistry.

 

[Anonymous]

Is there a chance, just maybe, that years ago, people vacuumed the cc too much and took this stuff out? That was what we were "supposed" to do.

Sure, however there was the school that you didn't need to vaccum it as well.

I havent vacuumed in about a year or more, and I noticed that suddenly, a whole ecosystem popped up. The creatures, I surmise, are eliminating this detrius quickly.

How do you know you have little detritus? Have you been stirring up the cc to check?

With more and more about the debate on dsb vs bare bottom vs this and that, and the continual stories of having to switchout sand beds every few years, I am just wondering, do we need to look to a different method, perhaps.

Careful not to generalize those stories. The are people who don't change out their sand, and people who recommend not touching it at all. Further, there are examples of just about every style of reef husbandry working very well and examples of them crashing.

Protein skimmers have helped and werent in wide usage when cc was more popular. Perhaps this one device, coupled with cc, made the difference now?

I don't think so.

I just dont see the build up along the glass that I have seen in some sand beds. Also, when I have to dig into the cc for whatever reason, I see very little of any particulate come up from it. I am sure there is some detrius, there probably has to be some.

I am surmising that perhaps the life in the substrate balances this detrius out.

I know there is no one way to do anything in this hobby. People have had success and failures in every aspect.

All I am saying is that what was once overlooked as something not viable (cc) many years ago, well, could it be POSSIBLE that now with newer methods (skimmer), this once overlooked substrate works hand in hand with a skimmer?

Seems many people who have cc now, and a skimmer, are reporting 0 rates, where before skimmers, cc was thought to be a "nitrate factory."

 

[Anonymous]

Is there a chance, just maybe, that years ago, people vacuumed the cc too much and took this stuff out? That was what we were "supposed" to do.

Sure, however there was the school that you didn't need to vaccum it as well.

I havent vacuumed in about a year or more, and I noticed that suddenly, a whole ecosystem popped up. The creatures, I surmise, are eliminating this detrius quickly.

How do you know you have little detritus? Have you been stirring up the cc to check?

With more and more about the debate on dsb vs bare bottom vs this and that, and the continual stories of having to switchout sand beds every few years, I am just wondering, do we need to look to a different method, perhaps.

Careful not to generalize those stories. The are people who don't change out their sand, and people who recommend not touching it at all. Further, there are examples of just about every style of reef husbandry working very well and examples of them crashing.

Protein skimmers have helped and werent in wide usage when cc was more popular. Perhaps this one device, coupled with cc, made the difference now?

I don't think so.

I just dont see the build up along the glass that I have seen in some sand beds. Also, when I have to dig into the cc for whatever reason, I see very little of any particulate come up from it. I am sure there is some detrius, there probably has to be some.

I am surmising that perhaps the life in the substrate balances this detrius out.

I know there is no one way to do anything in this hobby. People have had success and failures in every aspect.

All I am saying is that what was once overlooked as something not viable (cc) many years ago, well, could it be POSSIBLE that now with newer methods (skimmer), this once overlooked substrate works hand in hand with a skimmer?

Seems many people who have cc now, and a skimmer, are reporting 0 rates, where before skimmers, cc was thought to be a "nitrate factory."

 

[Anonymous]

I stopped vacuuming, and I noticed a lot more life top to bottom. My layer is about, geez, guessing a bit here, but about 2-3" or so.

When I see dsb, I notice very little life in the top layers, and none below that. It is dead, or seems most likely to be.

The DSB 'experts' would tell you that that bed is not being kept properly. In my octopus system I have a deep sand/muck bed. Its teeming with life. For the most part, when I had a DSB, it was also teeming.

Bare bottom, would, perhaps have MORE detriss, because you dont have the bristles, the little starfish (please, what is that species of starfish called...they look like tiny brittles?) and all of the other usual suspects that usually live in the LR and can devour it.

This is also the thing that I feel that got DSB's in trouble. The little critters don't make the detritus vanish. Thats not possible. They can break down some of it, but the 10% rule comes into effect very quickly. Even in the wild, the detritus doesn't get consumed, rather it get flushed out of the reef systems to settle in lagoons or the abyssal plain.
In a cc, I wouldn't think that you would have any more or any less detritus than in any other type of system.
In a BB system you do have the bristles and micro stars and all the other usual suspects (maybe not spaghetti worms though). Also, the point of most BB systems is to not allow the detritus to settle at all, but to keep it in suspension so it gets removed by filtration or skimmers.

Dont forget, skimmers now can take care of a lot that usually in the past could not be removed. SO now we have the skimmers taking out the little stuff, and the creatures in the LR and cc taking out the bigger stuff.

I think that is a little off base. The skimmer can only take out what gets to the skimmer. If the detritus is allowed to settle in the tank before it gets to the skimmer, the skimmer cant do anything about it.

And it was prompted by hearing about another tank failure and having to start over. Maybe sand really isnt the way to go for the AVERAGE hobbyist.

I am sure sand can be supported easily by the true, pure hobbyist who is devoted to the hobby, but maybe for people like me, who like the hobby, but dont really have the time or energy tomake it their one hobby, but enjoys it, maybe this cc works long term, easier than sand.

I think its all system dependent. I think in either a sand or cc system you run about the same risks of a crash or not a crash. The myth of the DSB was that you could set it up and not have to do anything to it, and I think believing the same about cc would lead to the same types of problems.

I feel sand only works in the ocean, because of the incredible, unfathomable diversity of life in and around it. But in a closed system, I feel it inevitably dies, by creating a dead zone. It seems more and more that is becoming common.

CC seems to solve this one aspect.

Sand generally doesn't work that way around reef systems. In almost all the wild reefs I have seen, the sand is way below the coral and is pretty much empty of life and is pretty clean. In lagoonal areas you see critters like you do in a DSB - and that sand is full of detritus.

What you wrote makes a lot of sense. However, I only beg to differ that there is absolutely no way you can compare the living oceans and reefs to our closed systems. The bio-diversity is just too incredible and massive to fathom in real life vs. our systems.

We do not have the luxury of having and lagoonal systems nearby, the volume to do so.

We can use t as a baseline, perhaps, but the comparison, I just dont buy it.

The only other point is the skimmer...I know it can only take what is going by the intake, but I am theorizing that ALL of it will eventually get to the skimmer in a cc setting, much more so than a dsb, as I have seen.

The nature of the cc seems to allow it to be broken up and RELEASED more readily.

Obviously, you and Len and a few others are experts at this, and I am pretty intermediate on the whole. Especially with the usage of dsb's, as I have never had one for a long duration. But I think sometimes the simplest explanations and observations can have merit too.

 

[Anonymous]

What you wrote makes a lot of sense. However, I only beg to differ that there is absolutely no way you can compare the living oceans and reefs to our closed systems. The bio-diversity is just too incredible and massive to fathom in real life vs. our systems.

I agree and I don't think I was trying to make the comparison, rather, I was pointing out that sand doesn't generally 'work' the way you were mentioning in the ocean.

[quoite]We do not have the luxury of having and lagoonal systems nearby, the volume to do so.[/quote]

Some of us do - and remember that most of the reef detritus doesn't go to lagoons, most goes to the abyssal plain.

The only other point is the skimmer...I know it can only take what is going by the intake, but I am theorizing that ALL of it will eventually get to the skimmer in a cc setting, much more so than a dsb, as I have seen.

The nature of the cc seems to allow it to be broken up and RELEASED more readily.

I don't think that is substrate dependent, but flow and circulation dependent.

Obviously, you and Len and a few others are experts at this, and I am pretty intermediate on the whole. Especially with the usage of dsb's, as I have never had one for a long duration. But I think sometimes the simplest explanations and observations can have merit too.

I don't know about the 'expert' idea, but we have read and experienced a whole bunch. All observation have merit, its the explanations that need to be looked at carefully and critically.

 

[Anonymous]

What you wrote makes a lot of sense. However, I only beg to differ that there is absolutely no way you can compare the living oceans and reefs to our closed systems. The bio-diversity is just too incredible and massive to fathom in real life vs. our systems.

I agree and I don't think I was trying to make the comparison, rather, I was pointing out that sand doesn't generally 'work' the way you were mentioning in the ocean.

[quoite]We do not have the luxury of having and lagoonal systems nearby, the volume to do so.

Some of us do - and remember that most of the reef detritus doesn't go to lagoons, most goes to the abyssal plain.

The only other point is the skimmer...I know it can only take what is going by the intake, but I am theorizing that ALL of it will eventually get to the skimmer in a cc setting, much more so than a dsb, as I have seen.

The nature of the cc seems to allow it to be broken up and RELEASED more readily.

I don't think that is substrate dependent, but flow and circulation dependent.

Obviously, you and Len and a few others are experts at this, and I am pretty intermediate on the whole. Especially with the usage of dsb's, as I have never had one for a long duration. But I think sometimes the simplest explanations and observations can have merit too.

I don't know about the 'expert' idea, but we have read and experienced a whole bunch. All observation have merit, its the explanations that need to be looked at carefully and critically.[/quote]

Sorry, seemed you were comparing the function of sand in a dsb aquarium to the way it functions in the ocean.

Don't you agree, based on the porous nature of cc vs. dsb, that the flow/circulation through this substrate must be greater? It just seems that way in comparison.

I am not asking for a blessing, but do you think given the results people ar ehaving now with cc and skimmers, that cc can be more considered a viable option now, where before it was thought of as a nitrate factory or of no use?

 

[Anonymous]

I don't think you get more flow though cc than sand.

I honestly don't know of many people running cc.
Putting a skimmer on a cc tank doesn't necessarily make it less of a nitrate factory, it just means you are able to export the nitrate faster. Personally, I think it makes more sense to get rid of the factory in the first place. YMMV.

 

[mr_X]

i don't want to vaccum my substrate. i want all the life to be seen from the side of the glass. every time i vaccum, i find all sorts of life in my waste container. it depresses me.
i use a crushed coral/live sand mix.
the reason i am thinking of getting rid of the crushed coral is- it's ugly.
it has coralline and whatever else grows on live rock growing on it.

what is the right thing here? maybe just stir it up every so often and let the skimmer get it?
that is what i do with my refugium (a decent amount of live rock rubble in there)
i dump gallons of top off water in there vigorously, to shake up things.
do i have the best of both worlds? (after the short time my tank has been running, the cc has somewhat come to the top of the bed and the sand is below)
8O

 

[Anonymous]

its anecdotal, but so far, I've had nothing but problems with DSBs, however my first reeftank had a deepish bed of CC and I not a single problem EVER

Hate to ask, but can you give the methods at the time?

Did you vacuum? Did you have a skimmer? How old was the cc bed?

Anything you can add.

Thanks bro!

I really want to learn more about this one aspect.

46 gallon bowfront, 330 watts PC, CPR Bak-Pak skimmer, 40 lbs CC and 48 pounds live rock.No Sump. Never vacuumed the CC ever. and no water changes - never once had a problem in the 3 years it was set up.

 

[Anonymous]

I don't think you get more flow though cc than sand.

Strictly speaking, you do. The large angular grains interrupt the fluid boundary layer at the grain-water interface and cause turbulence that forces water through the sediment pores. Very fine sediments tend to not interup the layer, so the flow just tends to pass over the bed.

 

[Anonymous]

I don't think you get more flow though cc than sand.

I honestly don't know of many people running cc.
Putting a skimmer on a cc tank doesn't necessarily make it less of a nitrate factory, it just means you are able to export the nitrate faster. Personally, I think it makes more sense to get rid of the factory in the first place. YMMV.

But my trates are 0, as it seems other people's cc tanks are.

And are you sure about the cc not allowing water to "flow through" it?

I would think it would allow water to move through it because of its nature and uneven surfaces?

 

[Anonymous]

what is the right thing here?

I dont think there is a right thing. I think it totally depends on too many factors to say one method is better than another. As long as everything is healthy and happy, everything else is asthetics.

All I am saying is that what was once thought of as a poor selection for substrate (cc) may actually not only be acceptable in most cases, but in some, may be the preference. Vice versa for other applications.

I dont vacuum anymore, pretty much for the reasons you stated...I hated seeing things alive in the water I took out, and it was a pain to get them back into the tank.

I think letting it take care of itself in this respect seems like the better way for cc. Allowing the life to grow and take care of the bed. I think vacuuming, maybe, hurt the bed long term?

 

[Anonymous]

I don't think you get more flow though cc than sand.

Strictly speaking, you do. The large angular grains interrupt the fluid boundary layer at the grain-water interface and cause turbulence that forces water through the sediment pores. Very fine sediments tend to not interup the layer, so the flow just tends to pass over the bed.

:lol: Yea, THATS what I was trying to say. Thanks!

 

[Anonymous]

I don't think you get more flow though cc than sand.

Strictly speaking, you do. The large angular grains interrupt the fluid boundary layer at the grain-water interface and cause turbulence that forces water through the sediment pores. Very fine sediments tend to not interup the layer, so the flow just tends to pass over the bed.

Can you qualify the 'strictly speaking'? How far down into the bed does the turbulence go?

 

[Anonymous]

I don't think you get more flow though cc than sand.

I honestly don't know of many people running cc.
Putting a skimmer on a cc tank doesn't necessarily make it less of a nitrate factory, it just means you are able to export the nitrate faster. Personally, I think it makes more sense to get rid of the factory in the first place. YMMV.

But my trates are 0, as it seems other people's cc tanks are.

I know! A tank that has 0 phosphates because of phosphate removing media has 0 phosphates. I still think it would be better to remove the source of the phosphates than to run the media.

And are you sure about the cc not allowing water to "flow through" it?

I think it depends on what you mean by 'flow through'. General Disarray will hopefully chime in again.

 

[Anonymous]

I don't think you get more flow though cc than sand.

Strictly speaking, you do. The large angular grains interrupt the fluid boundary layer at the grain-water interface and cause turbulence that forces water through the sediment pores. Very fine sediments tend to not interup the layer, so the flow just tends to pass over the bed.

Can you qualify the 'strictly speaking'? How far down into the bed does the turbulence go?

Further down the bed than the flow would go in a very fine deep sandbed, where there would be no turbulence at all because the grains aren't big enough to interupt the layer. Good enough? And not very much deeper than the first one or two grain layers.

 

[Anonymous]

I don't think you get more flow though cc than sand.

Strictly speaking, you do. The large angular grains interrupt the fluid boundary layer at the grain-water interface and cause turbulence that forces water through the sediment pores. Very fine sediments tend to not interup the layer, so the flow just tends to pass over the bed.

Can you qualify the 'strictly speaking'? How far down into the bed does the turbulence go?

Further down the bed than the flow would go in a very fine deep sandbed, where there would be no turbulence at all because the grains aren't big enough to interupt the layer. Good enough? And not very much deeper than the first one or two grain layers.

Perfect.
I had the feeling it wasn't all that deep. I have a hard time believing that one or two grain layers makes a significant difference, but you are the genius!