Tell me about deep sandbeds/ removing mechanical filtration

[garbled]

The theory is more or less that when you keep a DSB or plenum, because you want the heavy microfauna population in the sand, and actively cultivate it, that they also contribute greatly to the food web in the water column itself, similar to what you want. Many people who ran these, myself included, would run them skimmerless, because the fear was the skimmer would actively murder the larvae. Same with filter socks or mechanical filtration. That's not to say a hybrid approach can't be done.

The short answer however is, like many of the highly complex processes in an aquarium, the DSB is not fully understood. Even among the 4-5 people here who use them and are telling you about them, there is alot of disagreement as to how they work or what to do.

Do they work? Yes.
How? Maybe this, maybe that?
What is the exact recipie for success with one? Nobody knows, but there is a ton of information on older posts on older boards about them. Really I feel the right answer is to read alot, discuss alot, and kinda form your own ideas and opinions and try them. This is not the territory of "do these steps for success". This is the territory of "I like the idea of what this does, and want to experiment to learn more about what could be a better solution."

 

[Dr. Jim]

I just skimmed thru this thread so I apologize if this has already been said.....

I believe it was the early 90's when the plenum was introduced. At that time, the explanation given was that the layer of water beneath the substrate would create a hypoxic (low oxygen) region which would prevent any anaerobic conditions from forming which could lead to toxic hydrogen sulfide being produced and wiping out the tank. But the low level of oxygen was enough to allow the growth of nitrogen-fixing bacteria to convert nitrates to nitrogen gas. It seems, today, that many people don't seem to worry about the possibility of hydrogen sulfide toxicity, (which I don't quite understand).

In '94, I set up a plenum in a 500 gal tank. I cut 3/4" slices of a 3" PVC pipe and spread them around the floor of the tank to support eggcrate that was put on top of them. Two layers of mosquito netting was laid down, then 4" of dolomite. (Dating back to the 60's, dolomite was the most commonly available substrate). When "bare-bottom" came into vogue years later, I revamped the tank and got rid of the plenum. Much of the dolomite turned into solid bricks. I can't really say if I found any benefit to the system, but I didn't have a way to compare it to a similar tank without the plenum. (25 years ago, there were plenty of reasons why a tank might fail.)

 

[duberii]

You have fallen into the man principle.

At night the back of my tank is crawling with amphipods. It isn't the size of the wand it is the magic in it. I think that the plenum/DSB helps with is balance and that doesn't mean it needs to be bigger for that to happen. The constant addition IMO is the key.

Constant addition of what exactly?

 

[duberii]

I just skimmed thru this thread so I apologize if this has already been said.....

I believe it was the early 90's when the plenum was introduced. At that time, the explanation given was that the layer of water beneath the substrate would create a hypoxic (low oxygen) region which would prevent any anaerobic conditions from forming which could lead to toxic hydrogen sulfide being produced and wiping out the tank. But the low level of oxygen was enough to allow the growth of nitrogen-fixing bacteria to convert nitrates to nitrogen gas. It seems, today, that many people don't seem to worry about the possibility of hydrogen sulfide toxicity, (which I don't quite understand).

In '94, I set up a plenum in a 500 gal tank. I cut 3/4" slices of a 3" PVC pipe and spread them around the floor of the tank to support eggcrate that was put on top of them. Two layers of mosquito netting was laid down, then 4" of dolomite. (Dating back to the 60's, dolomite was the most commonly available substrate). When "bare-bottom" came into vogue years later, I revamped the tank and got rid of the plenum. Much of the dolomite turned into solid bricks. I can't really say if I found any benefit to the system, but I didn't have a way to compare it to a similar tank without the plenum. (25 years ago, there were plenty of reasons why a tank might fail.)

I can actually answer the question about hydrogen sulfide! The hydrogen sulfide comes about when something dies in the sandbedin the anaerobic zone. The creatures that can survive in that area tend to produce hydrogen sulfide as they break down the dead organism. Thus, only if you stir the sandbed and trap oxygen breathing organisms is the anoxic zone will the hydrogen sulfide be produced (or if a shallow sandbed is rapidly converted into a DSB by placing a thick layer of sand over the sandbed, effectively suffocating all life in the sand). Otherwise, any waste that would produce hydrogen sulfide would instead be filtered through the oxygenated layer and the low oxygen area, which will convert any waste into nitrates, which cannot be converted into hydrogen sufide.

 

[G Santana]

In my extensive experience, DSB are very successful for 2 years and then crash (even with the use of a plenulum). Everyone has different results. I am tempted to try again with the use of an algae scrubber and E-phosphate, but my Barebottom looks great (that's what she said).

When I was first in the hobby, DSB were all the rage, I had two, but I never had success until trends started towards shallow or bare bottom.
I switched to bare bottom and then I realized success.
That doesn't mean folks had and continue to have success with DSB. It just didn't work for me.

 

[duberii]

The theory is more or less that when you keep a DSB or plenum, because you want the heavy microfauna population in the sand, and actively cultivate it, that they also contribute greatly to the food web in the water column itself, similar to what you want. Many people who ran these, myself included, would run them skimmerless, because the fear was the skimmer would actively murder the larvae. Same with filter socks or mechanical filtration. That's not to say a hybrid approach can't be done.

The short answer however is, like many of the highly complex processes in an aquarium, the DSB is not fully understood. Even among the 4-5 people here who use them and are telling you about them, there is alot of disagreement as to how they work or what to do.

Do they work? Yes.
How? Maybe this, maybe that?
What is the exact recipie for success with one? Nobody knows, but there is a ton of information on older posts on older boards about them. Really I feel the right answer is to read alot, discuss alot, and kinda form your own ideas and opinions and try them. This is not the territory of "do these steps for success". This is the territory of "I like the idea of what this does, and want to experiment to learn more about what could be a better solution."

I usually take most advice I get with a grain of salt- perhaps not even because people don't understand what is happening, but usually because what works for them won't work for everybody. I usually try to get into what can go wrong- if the worst case is that nothing happens or I waste a bit of my time, I'll give it a shot. This seems to be one of those cases- I know the main killers of a DSB being stirring or the predation of the life in a sandbed- otherwise the fear of a tank crash seems pretty unlikely. I'm thinking of just adding a bunch of play sand in my sump- that seems like the easiest way to get results (if i can get results).

 

[duberii]

When I was first in the hobby, DSB were all the rage, I had two, but I never had success until trends started towards shallow or bare bottom.
I switched to bare bottom and then I realized success.
That doesn't mean folks had and continue to have success with DSB. It just didn't work for me.

From what I've seen, the main component of a sandbed is biodiversity- if you don;t seed the sandbed with something, it is rather unlikely that the sandbed will function as intended. I'm tallking to a bunch of local reefers and hope to get a cupful of their sand to get as much life into the sandbed as possible- I may try to set up a 10 gallon and get the sandbed running there, then seed my main tank to ensure that I don't intoduce anything nasty.

 

[garbled]

I'm thinking of just adding a bunch of play sand in my sump- that seems like the easiest way to get results (if i can get results).

The rage used to be the Home Depot carribean white sand, because it was super-cheap, and aragonite based. That's what my main 800 tank runs, I run about a 5" DSB, but IMHO 4" is better. I only run 5 because the tank is so deep otherwise I can't reach the bottom.

The general idea is always that these tanks take a *long* time to "cycle". You are dealing with different cycles here than just your normal ammonia/nitrite/nitrate cycle. You have a cycle of sandbed fauna. Each lifeform kinda has it's own cycle where it blooms, dies off, then either stabilizes or goes extinct. You kinda have to keep up on what is going on down there. Are the little mysid's doing ok? Check at night with a red flashlight. What about the gammarus? The bristleworms? other worms, other tiny things, etc etc. Take some time in front of the tank to assay your population every few weeks.

I find that a DSB takes about 9 months to fully stabilize. You want to feed the bed itself, with sinking foods at first (assuming no fish). I like to feed it at night when it's dark. If you have fish, this is less of an issue.

Don't be afraid to buy packs of sandbed fauna and replenish. Sometimes stuff dies off, this is especially true if it suddenly blooms to a crazy population and then starves. Constant replenishment with pods, micro-critters, etc is just part of the stocking routine and "filter" maintenance.

I've heard tons of terror stories about how people are afraid of the "sulfur volcano" in a DSB. I've never actually read a single story about one really happening. Just kinda vague "my tank crashed and I blame the DSB, so it must have been H2S." I suspect most tank crashes with DSB's are either just "my tank crashed because of some other random thing" or "I never paid attention to the sandbed fauna."

This was the big proponent of the DSB theory, finally found his website. I haven't read this particular page yet, but his articles and posts were top notch quality and I would highly recommend reading anything he wrote on the subject.

Ron Schmeck Deep Sand Beds

 

[Dr. Jim]

I can actually answer the question about hydrogen sulfide! The hydrogen sulfide comes about when something dies in the sandbedin the anaerobic zone. The creatures that can survive in that area tend to produce hydrogen sulfide as they break down the dead organism. Thus, only if you stir the sandbed and trap oxygen breathing organisms is the anoxic zone will the hydrogen sulfide be produced (or if a shallow sandbed is rapidly converted into a DSB by placing a thick layer of sand over the sandbed, effectively suffocating all life in the sand). Otherwise, any waste that would produce hydrogen sulfide would instead be filtered through the oxygenated layer and the low oxygen area, which will convert any waste into nitrates, which cannot be converted into hydrogen sufide.

Yes, I know that. What I meant when I said, "I don't understand why" is that I meant that I didn't understand why "today, many people don't seem to worry about the possibility of hydrogen sulfide toxicity." Sorry if I didn't make that clear.

 

[duberii]

The rage used to be the Home Depot carribean white sand, because it was super-cheap, and aragonite based. That's what my main 800 tank runs, I run about a 5" DSB, but IMHO 4" is better. I only run 5 because the tank is so deep otherwise I can't reach the bottom.

I heard that you want to use silicious sand to prevent the sandbed from solidifying, since apparently the sandbed can get decently acidic, causing the sand to dissolve. I have never seen the home depot carribean white sand, but I'll certainly check it out. As for the depth of the sandbed- why do you say 4" is better?

The general idea is always that these tanks take a *long* time to "cycle". You are dealing with different cycles here than just your normal ammonia/nitrite/nitrate cycle. You have a cycle of sandbed fauna. Each lifeform kinda has it's own cycle where it blooms, dies off, then either stabilizes or goes extinct. You kinda have to keep up on what is going on down there. Are the little mysid's doing ok? Check at night with a red flashlight. What about the gammarus? The bristleworms? other worms, other tiny things, etc etc. Take some time in front of the tank to assay your population every few weeks.

I'm hoping I can avoid doing all the seeding parts- I am a college kid so unless I can crowdfund ( ) I'm working on a budget. I'm thinking of setting up another tanbk specifically for amphipod breeding (a 10 gallon) plus adding a DSB to my refugium. If the biodiversity crashes in one, I hopefully can seed the other witha bit of sand from the first. I'm also hoping that my sandbed in the display stays pretty healthy so I could seed from that as well.

I find that a DSB takes about 9 months to fully stabilize. You want to feed the bed itself, with sinking foods at first (assuming no fish). I like to feed it at night when it's dark. If you have fish, this is less of an issue.

Do you think the DSB will destabilize the rest of the tank, or will it just have fluctuating populations up until that point? I'd rather not introduce another possible failing point to my tank- I think I have enough haha

I've heard tons of terror stories about how people are afraid of the "sulfur volcano" in a DSB. I've never actually read a single story about one really happening. Just kinda vague "my tank crashed and I blame the DSB, so it must have been H2S." I suspect most tank crashes with DSB's are either just "my tank crashed because of some other random thing" or "I never paid attention to the sandbed fauna."

I mean I've seen a few videos- the hydrogen sulfide bubbles are surrounded by black sand- it's pretty crazy actually. I'm not sure if it's the sulfide that makes it black or the bacteria, but it's pretty crazy to see. I have never seen any documentation of a tank crash or anything crazy regarding hydrogen sulfide, and it usually goes away on its own as the life shuffles around the sandbed.

 

[duberii]

Yes, I know that. What I meant when I said, "I don't understand why" is that I meant that I didn't understand why "today, many people don't seem to worry about the possibility of hydrogen sulfide toxicity." Sorry if I didn't make that clear.

Sorry about that- maybe somebody reading along learned something from that I accidentally left a bucket of sand in a sealed bucket for a few weeks, and opened it up and it was jet black and smelled like a dead body. Certainly not something you want to mess around with. I think that hydrogen sulfide is one of the smaller concerns in keeping a reef tank- there are pleanty of things that can harm us that we keep, but it certainly is something you have to keep in mind.

 

[Dr. Jim]

Sorry about that- maybe somebody reading along learned something from that I accidentally left a bucket of sand in a sealed bucket for a few weeks, and opened it up and it was jet black and smelled like a dead body. Certainly not something you want to mess around with. I think that hydrogen sulfide is one of the smaller concerns in keeping a reef tank- there are pleanty of things that can harm us that we keep, but it certainly is something you have to keep in mind.

I wasn't really worrying about the hydrogen sulfide harming us....in fact that didn't even cross my mind! It was the corals I was concerned about. (....if I'm reading you properly).

 

[duberii]

I wasn't really worrying about the hydrogen sulfide harming us....in fact that didn't even cross my mind! It was the corals I was concerned about. (....if I'm reading you properly).

Valid concern- some corals can cost more than a medical bill

 

[duberii]

I'm looking at adding something like these shrimp, but would they eat critters in the sandbed? I am a super heavy feeder, so I'm not really worried about competition for food- I'm more concerned that they would eat pods and such, which is no good obviously Any thoughts?

 

[vlangel]

I'm looking at adding something like these shrimp, but would they eat critters in the sandbed? I am a super heavy feeder, so I'm not really worried about competition for food- I'm more concerned that they would eat pods and such, which is no good obviously Any thoughts?

I have always run DSBs and never had one turn toxic. I worked for a LFS and my boss built most of tanks he set up with DSBs. One 250 gallon tank he built for a friend of mine almost 20 years ago is still running with the original sandbed in it.

I choose a DSB because it is lower maintenance than SSBs. I merely dance my fingers across the surface of the sand once a month or so to oxygenate the top inch. I like that the anaerobic bacteria help with denitrification and that pods and worms can dwell in the sandbed. I am careful not to choose creatures that could eradicate the life living in the sandbed like a sand sitting starfish. I do choose creatures like nassarius snails to stir the surface of the sand. My display and refugium have DSBs.

I do not run filter socks or a protein skimmer and I feed heavy. The refugium has macro algae and seagrass which take up nutrients very effectively. I only do a 10% water change every other week now that the tank has been up and running 4 years and is very stable.

This method has worked very well for me and I wish you the best with your tank.

0 new items by Dawn Gilson

photos.app.goo.gl

 

[garbled]

I'm pretty sure grass shrimp are basically predators.

 

[A2dahlberg]

I know I haven't started my salt water tank yet but both of my fresh tanks are DSB. This series of videos really help me understand and set up my tanks in this way. He uses the term no water change but I think the idea is the same. Here's the series: Jay's aquarium - YouTube. I'm going to be doing my EVO 13.5 with DSB. I love this kind of stuff too.

 

[A2dahlberg]

I know I haven't started my salt water tank yet but both of my fresh tanks are DSB. This series of videos really help me understand and set up my tanks in this way. He uses the term no water change but I think the idea is the same. Here's the series: Jay's aquarium - YouTube. I'm going to be doing my EVO 13.5 with DSB. I love this kind of stuff too.

 

[A2dahlberg]

trying to delete these posts. just the duplicate one.

 

[duberii]

I have always run DSBs and never had one turn toxic. I worked for a LFS and my boss built most of tanks he set up with DSBs. One 250 gallon tank he built for a friend of mine almost 20 years ago is still running with the original sandbed in it.

I choose a DSB because it is lower maintenance than SSBs. I merely dance my fingers across the surface of the sand once a month or so to oxygenate the top inch. I like that the anaerobic bacteria help with denitrification and that pods and worms can dwell in the sandbed. I am careful not to choose creatures that could eradicate the life living in the sandbed like a sand sitting starfish. I do choose creatures like nassarius snails to stir the surface of the sand. My display and refugium have DSBs.

I do not run filter socks or a protein skimmer and I feed heavy. The refugium has macro algae and seagrass which take up nutrients very effectively. I only do a 10% water change every other week now that the tank has been up and running 4 years and is very stable.

This method has worked very well for me and I wish you the best with your tank.

0 new items by Dawn Gilson

photos.app.goo.gl

That is such a cool tank! I notice you have some feather duster worms- do you feed them, or does the microfauna handle that for you? I would love to pick up some filter feeders for my tank but I'm trying to avoid needless casualties.