Survey Reefers re: vacuuming sand bed.

[BeanAnimal]

Actually bioturbation prevents suffocation.

And with sufficient flow and activity in the sandbed, excess detritus is effectively removed with particle filters.

How are you defining detritus, sufficient flow and activity?

Sure, a sandbed continually churned in a storm of flow with large sifters like snails, large worms, starfish, etc. may not accumulate anything, including small particulate aragonite, but show me a home aquarium that has that much flow and that many large sand sifters. They reality is we can't have that much flow in our captive systems and our sand becomes a trap for everything, both active and inert that does not make it to the mechanical filter. Moreover, with the amount of flow required to effectively keep all of that material from accumulating, the aragonite would also pulverize itself. You are essentially talking about a fluidized bed!

Oddly, you stated above that we "over stir" our systems. You can't have it both ways

 

[Dburr1014]

I use a turkey baster to "turnover" the sand when I think about it. Unfortunately, I don't think about it very often. And unfortunately, I can't get any siphon in there to get all the cracks and crevices, so this is why I use a turkey baster.

 

[Alexraptor]

I am not here to debate what is over filtration or what organisms should be allowed to thrive or why. The reality is that long term, there is very little difference between the two systems and most of "bio diversity" ends up pretty similar and is transported around as we trade fish corals and even cups of sand with each other.

Agree to disagree.

How are you defining detritus, sufficient flow and activity?

Sure, a sandbed continually churned in a storm of flow with large sifters like snails, large worms, starfish, etc. may not accumulate anything, including small particulate aragonite, but show me a home aquarium that has that much flow and that many large sand sifters. They reality is we can't have that much flow in our captive systems and our sand becomes a trap for everything, both active and inert that does not make it to the mechanical filter. Moreover, with the amount of flow required to effectively keep all of that material from accumulating, the aragonite would also pulverize itself. You are essentially talking about a fluidized bed!

Oddly, you stated above that we "over stir" our systems. You can't have it both ways

I'm not talking about anything of the kind.

What I'm talking about is having sufficient flow so that lightweight particles that gets naturally stirred up into the water column, via bioturbation, gets carried off to the filters, rather than simply just settling back down.

 

[BeanAnimal]

Agree to disagree.

If that makes you feel better. Otherwise, I suggest taking a look at few of the recent biome studies and coming to the realization that most systems converge to a somewhat predictable endpoint over time. Our systems support a fairly small subset of the macro and micro fauna that we import and as we trade corals, fish and rocks, we spread around what does flourish but even without significant import, we still all end up with a very similar small subset comprised of organisms that compete well on our closed systems.

What I'm talking about is having sufficient flow so that lightweight particles that gets naturally stirred up into the water column, via bioturbation, gets carried off to the filters, rather than simply just settling back down

Right, but in reality our sandbeds, deep or shallow, high flow or not, sand sifters or not, become settling grounds for tremendous amounts of particulate matter, both active and inert. The flow required to prevent this from happening would fluidize the sandbed.

I am not trying to be contrary here, but rather pointing out the realities of our tiny captive systems. There is theory and there is practice/reality. In practice, no matter how hard most of us try, we end up with a fairly predictable biome and sandbed full of particulate matter. It is just the reality of a "reef" at this scale.

 

[Gumbies R Us]

I use a turkey baster to "turnover" the sand when I think about it. Unfortunately, I don't think about it very often. And unfortunately, I can't get any siphon in there to get all the cracks and crevices, so this is why I use a turkey baster.

I do this as well whenever I think about it, which isn't often haha

 

[Alexraptor]

If that makes you feel better. Otherwise, I suggest taking a look at few of the recent biome studies and coming to the realization that most systems converge to a somewhat predictable endpoint over time. Our systems support a fairly small subset of the macro and micro fauna that we import and as we trade corals, fish and rocks, we spread around what does flourish but even without significant import, we still all end up with a very similar small subset comprised of organisms that compete well on our closed systems.


Right, but in reality our sandbeds, deep or shallow, high flow or not, sand sifters or not, become settling grounds for tremendous amounts of particulate matter, both active and inert. The flow required to prevent this from happening would fluidize the sandbed.

I am not trying to be contrary here, but rather pointing out the realities of our tiny captive systems. There is theory and there is practice/reality. In practice, no matter how hard most of us try, we end up with a fairly predictable biome and sandbed full of particulate matter. It is just the reality of a "reef" at this scale.

Oh I don't disagree that our systems only support a small subset of organisms. I simply assert that live rock inetvitably provides greater diversity, no matter how you slice it. In particular, sand beds rely heavily on a variety of worms for effective bioturbidation to occur, something you won't get starting out with dry rock. Indeed, many people eschew live rock becuase of the "ick factor" that comes with worms.

My point was never about preventing particulate matter from settling in the sand bed, but rather quite the opposite: Embracing and managing it, and removing the excess particles that readily become waterborne. My apologies if I didn't articulate that clearly.

 

[revhtree]

Side note: you can create polls with threads and you could add one to this one.

 

[BeanAnimal]

Oh I don't disagree that our systems only support a small subset of organisms. I simply assert that live rock inetvitably provides greater diversity, no matter how you slice it. In particular, sand beds rely heavily on a variety of worms for effective bioturbidation to occur, something you won't get starting out with dry rock. Indeed, many people eschew live rock becuase of the "ick factor" that comes with worms.

Thank you for the response. I do agree that live rock does add to the diversity, but I don't think there is much difference between 5 pounds of live with 30 pounds of dry vs 30 pounds of live and 5 pounds of dry, especially if the "live" comes from the same place. I have always been a proponent of exchange a cup of sand or a handful of rubble with multiple sources. That said, it is becoming apparent that even with broadly diverse sources, things still tend to converge to a "typical" biome where the same subset of fauna survive long term. Even in the case of worms, I think most of us see many species come and go and prey we don't get any of ones that DON'T go if we get them.

My point was never about preventing particulate matter from settling in the sand bed, but rather quite the opposite: Embracing and managing it, and removing the excess particles that readily become waterborne. My apologies if I didn't articulate that clearly.

I think most struggle to find ways to manage it and remove it, some of us just ignore it! I have a shallow bed in areas, that has turned into a DSB in others. I do have two Randall's shrimp that appear to keep the deeper areas churned. I personally don't vacuum or stir the sandbed. I just don't want to deal with the mess and assume most of what has accumulated over 20+ years is inert. I could be wrong!

 

[Tavero]

Actually bioturbation prevents suffocation.

And with sufficient flow and activity in the sandbed, excess detritus is effectively removed with particle filters.

Well you were saying that "most systems" are too aggressively filtered and prevent complex food webs.
I thought you were talking about particle filters. Because having socks or a roller mat filter in your tank will definitely prevent filter feeders like feather duster worms from establishing themselves.

 

[TWYOUNG]

We are not debating a sterile system vs one stated with live rock. We are talking about a system started with only live rock vs one started with some live rock and your opinion that using any dry rock is a mistake.

As I stated, and has been shown by event recent biome tests, most systems end up in the same basic biome space after a modest period f time, like it or not. Sure, there is always a chance that that "one extra rock" brings in something new.. but how many "live rocks" is enough?

If you want to cite "pure mathematics" then you would want to count the organisms that CAN survive, vs those that typically DO survive against those that have NO CHANCE to survive and those that are WANTED and those that are UNWANTED.

I am not here to debate what is over filtration or what organisms should be allowed to thrive or why. The reality is that long term, there is very little difference between the two systems and most of "bio diversity" ends up pretty similar and is transported around as we trade fish corals and even cups of sand with each other.

Very interesting and I basically agree however after months of issues with dinoflagellates and nuisance algae I'm not sure how I'd approach starting a new tank if I did it again. Dry manufactured rock was great for creating a rock scape but I feel I'd like to use some ocean rock, at least in the sump if I did it again. Do you think that would significantly speed up the tanks maturation?

 

[BeanAnimal]

Very interesting and I basically agree however after months of issues with dinoflagellates and nuisance algae I'm not sure how I'd approach starting a new tank if I did it again. Dry manufactured rock was great for creating a rock scape but I feel I'd like to use some ocean rock, at least in the sump if I did it again. Do you think that would significantly speed up the tanks maturation?

Yes, rock pulled from (or cultured in) the ocean will help you to move along the maturation curve and certainly introduce diversity from the onset. There are downsides and I suggest following some of the guides on quarantine and observation for unwanted guests.

 

[sfin52]

#MODS can you help with survey

 

[jda]

I leave my sand alone for years at a time. I got a cucumber, which has divided, that is probably a decade old. I also have other sand critters.

I do vacuum my sand starting in about year four. 25% every quarter, so it takes the whole year.

I find that the inert grey suldge/gunk that settles in there can gum up the works, keep water from getting to the deeper parts for denitrification. I want to get that inert gunk out of there. This is one thing that I think that Dr. Ron got wrong - you have to get this garbage out... there are just some things that cannot be used by anything in a tank and they settle in the sand. Every 3-4 years is enough, IMO. You don't want to do it any more often or else it makes it hard for the sand to remove nitrate.

If you do a small section of sand and then allow the oxic and anoxic zones to repopulate before you move on, the sand critters tend to stay in the "fresh" areas more. This tells me that I am doing something good.

 

[Alexraptor]

Well you were saying that "most systems" are too aggressively filtered and prevent complex food webs.
I thought you were talking about particle filters. Because having socks or a roller mat filter in your tank will definitely prevent filter feeders like feather duster worms from establishing themselves.

There are magnitudes of filtering, even with particle filters.

Like, do I run a filter sock 24/7? Or do I only choose to run it only every other day? Every other week? Do I choose a 200-micron sock or a 50 micron sock? The former will trap larger particles, but allow many planktonic organisms to pass through.

Personally I tend to run regular filter floss in my systems for 12-24 hours, after water changes.

 

[Tavero]

I leave my sand alone for years at a time. I got a cucumber, which has divided, that is probably a decade old. I also have other sand critters.

I do vacuum my sand starting in about year four. 25% every quarter, so it takes the whole year.

I find that the inert grey suldge/gunk that settles in there can gum up the works, keep water from getting to the deeper parts for denitrification. I want to get that inert gunk out of there. This is one thing that I think that Dr. Ron got wrong - you have to get this garbage out... there are just some things that cannot be used by anything in a tank and they settle in the sand. Every 3-4 years is enough, IMO. You don't want to do it any more often or else it makes it hard for the sand to remove nitrate.

If you do a small section of sand and then allow the oxic and anoxic zones to repopulate before you move on, the sand critters tend to stay in the "fresh" areas more. This tells me that I am doing something good.

That's not how denitrification works.

You don't want anoxic conditions in a reef tank because it will encourage the creation of of hydogen sulfide. Anaerobic conditions are desirable but I'm gonna predict that almost none of the reef tanks are actually doing denitrification due to it. Most nitrates are removed from the water by coral and algae growth. Only systems that are specifically made to encourage denitrification due to an anaerobic stage are removing nitrogen that way. For example a deep sand bed or a denitrifator.

 

[jda]

Nope. It has worked like that for 30 years. 3 inches of sand is enough to have anoxic zones. My 3" sand beds have kept no3 at .1 for decades.

You have to bury raw organic matter in the sand for h2s to form. Most of the fear and talk about h2s is from internet myths and parroting... overblown. I could probably agree that a really messy tank without the sufficient organisms to consumer organics before they fall into the deeper regions might get some h2s, but these are edge cases.

In my healthy reef tanks since 1992, never smelled any h2s other than the occasional media reactor that I put away without cleaning it out first.

BTW - you can get anoxic zones in 1/2 inch of sand under rocks and things. All that you need i slow water movement where the o2 can get used up. Nobody ever smells h2s coming from these.

Dr RHF has talked a lot about how this is overblown and has written about it in his h2s article. Here is a pretty concise few posts and a link to the article.

Deep Sand Bed ......Hydrogen Sulfide question................ - Reef Central Online Community

Deep Sand Bed ......Hydrogen Sulfide question................ Reef Discussion

www.reefcentral.com

 

[Tavero]

There are magnitudes of filtering, even with particle filters.

Like, do I run a filter sock 24/7? Or do I only choose to run it only every other day? Every other week? Do I choose a 200-micron sock or a 50 micron sock? The former will trap larger particles, but allow many planktonic organisms to pass through.

Personally I tend to run regular filter floss in my systems for 12-24 hours, after water changes.

So what do you recommend?
You never specified a any filter size or filter duration, just said aggressive filtration. Now you just gave examples. When do you define aggressive filtration.

A friend of mine that runs a 200g tank introduced the standard red sea reef mat filter and over one year most of his feather duster worms disappeared.

It's not possible to reduce the filtration there. The system will change the floss by itself as soon it it clogged.

 

[BeanAnimal]

A friend of mine that runs a 200g tank introduced the standard red sea reef mat filter and over one year most of his feather duster worms disappeared.

It's not possible to reduce the filtration there. The system will change the floss by itself as soon it it clogged.

One may (and likely has) nothing to do with the other. Things like feather dusters and fan worms come and go based on numerous factors.

As far as reducing, sure you can partially bypass a filter roller if you are concerned about "over filtering".

 

[Tavero]

Nope. It has worked like that for 30 years. 3 inches of sand is enough to have anoxic zones. My 3" sand beds have kept no3 at .1 for decades.

You have to bury raw organic matter in the sand for h2s to form. Most of the fear and talk about h2s is from internet myths and parroting... overblown. I could probably agree that a really messy tank without the sufficient organisms to consumer organics before they fall into the deeper regions might get some h2s, but these are edge cases.

In my healthy reef tanks since 1992, never smelled any h2s other than the occasional media reactor that I put away without cleaning it out first.

BTW - you can get anoxic zones in 1/2 inch of sand under rocks and things. All that you need i slow water movement where the o2 can get used up. Nobody ever smells h2s coming from these.

Dr RHF has talked a lot about how this is overblown and has written about it in his h2s article. Here is a pretty concise few posts and a link to the article.

Deep Sand Bed ......Hydrogen Sulfide question................ - Reef Central Online Community

Deep Sand Bed ......Hydrogen Sulfide question................ Reef Discussion

www.reefcentral.com

I have worked in a water purification plant. There is a difference between anonoxic and anaerobic conditions. This isn't parroting from the internet this is talking from experience.

Yes anoxic conditions are possible in 1/2 in sand. They can even appear with no sand at all. I never said it wasn't possible. But it is undesirable because it promotes H2F production. And yes I have smelled h2s coming from fouling rock.

You said your tank worked for 30 years that way but how do you actually know there is denitrifation going on? And not just your coral using up all nitrogen?

Like I said anaerobic conditions are very specific.
No o2 for at least 15 min.
Organic Carbon present.
pH in a specific range.
Ect (there is more but I need to look it up)
Deviate from these conditions and Nitrobacter will just stop transforming nitrogen. In worst cases that anaerobic conditions switches anoxic and bacteria start fouling processes by digesting themselves.

 

[Tavero]

One may (and likely has) nothing to do with the other. Things like feather dusters and fan worms come and go based on numerous factors.

As far as reducing, sure you can partially bypass a filter roller if you are concerned about "over filtering".

That wasn't my question to Alexraptor though. My question was: What is his definition for aggressive filtration? In numbers. This is a genuine question.

Also the feather dusters disappeared after the introduction of the reef mat filter. He didn't even add any other fish for one year. Sure there may be other reasons and conditions but one significant one is starvation.