Anyone Running a Remote Deep Sand Bed/Macro 'Fuge For Nitrate Reduction?

[Fish Fan]

Hey all!

When I was dabbling in this hobby sometime about 2003 or so, I remember some reefers on the old RC were trying out Deep Sand Beds (DSB's) 6" deep or greater, or more specifically of interest for me, a Remote Deep Sand Bed (RDSB) for nitrate reduction. Remote, just meaning that the DSB was not in your tank, or necessarily even in your sump. And remote, meaning one could easily control the water flow through it, and take it offline if it goes squirely ;-)

Did this idea go anywhere? Is anyone out there running something like this?

Back then, I believe it was thought that for a RDSB you needed a very, very deep sand bed to see denitrification. Some were experimenting with those wrapping paper storage bins, which are relatively tall and narrow, if i remember correctly.

But now I'm thinking something like a 20 gallon long (or maybe 29) with maybe 6"-8" inches of a very fine sand, topped, in my case, with an inch or so of Tampa Bay Saltwater sand, which I am planning on for my display. The TBS sand is very course/chunky, and can hold the finer sand down, is the idea, not to mention seed some microbes, is the hope, lol!

Water would come in slowly from one short side of the 20L, flowing gently over the sand bed, and exiting the other side of the tank.

My thought was to either manually maintain this sand bed, little by little weekly, and/or pack this area with enough sand sifting/moving critters to keep it well maintained.

Then, the hamster wheel kept turning, and I wondered if I could make this 20L RDSB something of a "macro tank", with the DSB, macro algae, critters, dare I say a Mangrove.....

What do you guys think? Should I go back to 2003 lol??

Thanks for the help!

 

[Subsea]

If nitrate is your only focus then an easier design would be “anaerobic digester”.

“DENITRIFICATION (biological conversion of nitrate and nitrite to nitrous oxide and molecular nitrogen)

“Nutrient recycling: nitrate reduction (assimilation of nitrate–nitrogen in microbial protoplasm) “

I am very familiar with the concept of NNR. However, Julian Sprung Reef Aquarium Volume 3 shows denitrification & nitrification chemistry happening in close proximity of each other.

After 20 years with a 4” deep Jaubert plenum which is designed for NNR (Natural Nitrate Reduction), I found that the coral inhabitants consumed nitrate faster than I added it. I switched to a shallow reverse flow in display and made the sump a cryptic refugium.

I dose ammonia to keep up with nitrogen demand.

Global patterns of marine nitrogen fixation and denitrification​

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/97GB00077

 

[CrabMech]

I remember reading about those systems in the early 2000's but I never ran one personally. If I remember correctly--and this may well be wrong--the point was that the sand bed was deep enough that it had an area that was free of oxygen, and that's where the de-nitrifying bacteria lived. So, the idea was to disturb the sand bed as little as possible--in other words no sand sifters--because disturbing the sand bed would bring oxygen down where you didn't want it.
That said, I'm not sure about the wisdom of sand-sifting critters in there, but I'm sure you could keep macro algae and critters that weren't prone to dig too much.

 

[Fish Fan]

If nitrate is your only focus then an easier design would be “anaerobic digester”.

“DENITRIFICATION (biological conversion of nitrate and nitrite to nitrous oxide and molecular nitrogen)

“Nutrient recycling: nitrate reduction (assimilation of nitrate–nitrogen in microbial protoplasm) “

I am very familiar with the concept of NNR. However, Julian Sprung Reef Aquarium Volume 3 shows denitrification & nitrification chemistry happening in close proximity of each other.

After 20 years with a 4” deep Jaubert plenum which is designed for NNR (Natural Nitrate Reduction), I found that the coral inhabitants consumed nitrate faster than I added it. I switched to a shallow reverse flow in display and made the sump a cryptic refugium.

I dose ammonia to keep up with nitrogen demand.

Global patterns of marine nitrogen fixation and denitrification​

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/97GB00077

Thank you for the reply!

Are you basically saying the Julian Sprung decided that a deep sand bed wasn't worth it? I don't really know what an "anaerobic digester" is, but it sounds like what I'm hoping to do with a deep sand bed.

I remember reading about those systems in the early 2000's but I never ran one personally. If I remember correctly--and this may well be wrong--the point was that the sand bed was deep enough that it had an area that was free of oxygen, and that's where the de-nitrifying bacteria lived. So, the idea was to disturb the sand bed as little as possible--in other words no sand sifters--because disturbing the sand bed would bring oxygen down where you didn't want it.
That said, I'm not sure about the wisdom of sand-sifting critters in there, but I'm sure you could keep macro algae and critters that weren't prone to dig too much.

Yes, the idea is to have a sand bed that is so deep that hopefully an anoxic zone forms, and denitrification happens.

I proposed a 6"-8" Deep Sand Bed of very fine sand, topped with just a 1" layer of more course sand to hold things down. The "critters" would occupy that course sand layer on top, and not go fully down into the DSB. So only the top layer would get disturbed. That's the idea, anyway

 

[Fish Styx]

I run a 20 long remote DSB as a mangrove display fuge. A Wennerae Mantis lives in there- no issues with the DSB releasing anything harmful into the system.

 

[Fish Fan]

I run a 20 long remote DSB as a mangrove display fuge.

Now that's what I'm talking about lol!

Could you please share some more details, like how deep is the sand bed, what kind of sand did you use, do you "maintain" the sand or have critters, and does it seems to reduce nitrate?

Thank you very much!

 

[Fish Styx]

Now that's what I'm talking about lol!

Could you please share some more details, like how deep is the sand bed, what kind of sand did you use, do you "maintain" the sand or have critters, and does it seems to reduce nitrate?

Thank you very much!

Sure thing. The sandbed is about 7" deep on average (~6 in some, ~8 in others). It is layered, with the bottom inch being a mix of Fiji and miracle mud. The next 5 inches are a 50 / 50 mix of oolite and play sand. The top two inches are Tonga Reefflake.

It maintains itself, really. As far as critters, I have a Wennerae Mantis named "Murderbug" that lives there along with some hermits and a few small snails (both replenished frequently).

Lighting is set in a three-tiered setup, from top down: (3) Kessil A360WE, (2) full spectrum light bars, and (2) full spectrum spots. This allows lighting to hit the canopy in multiple places amd allow for penetration in to the display.

Flow handled by an Ecotech MP10.

Additionally, I have some live rock, soft corals, and a bunch of ornamental macros in there. How much does it reduce nitrates? No clue exactly, but the whole shebangbang definitely does. Plus, it's pretty cool to look at.

 

[TX_REEF]

I run a 20 long remote DSB as a mangrove display fuge. A Wennerae Mantis lives in there- no issues with the DSB releasing anything harmful into the system.

that is absolutely gorgeous! It puts my mini display sump fuge to shame:

 

[Fish Fan]

Sure thing. The sandbed is about 7" deep on average (~6 in some, ~8 in others). It is layered, with the bottom inch being a mix of Fiji and miracle mud. The next 5 inches are a 50 / 50 mix of oolite and play sand. The top two inches are Tonga Reefflake.

It maintains itself, really. As far as critters, I have a Wennerae Mantis named "Murderbug" that lives there along with some hermits and a few small snails (both replenished frequently).

Additionally, I have some soft corals and a bunch of ornamental macros in there. How much does it reduce nitrates? No clue exactly, but the whole shebangbang definitely does. Plus, it's pretty cool to look at.

Yes, very cool to look at lol! Thank you for the info! This is very similar to what I'm thinking. I used to have an N. wennerae in his own 10 gallon, he sadly died when the cheap ATO malfunctioned :-(. I very much want another. I'm planning a new tank and hoping to get around 100 pounds of TBS sand and about 50/50 each of their base rock and premium rock. I've got my fingers crossed that a mantis shows up in that order too

But your sand depth and the macros, and maybe even the mangroves are just what I am thinking.

 

[Fish Fan]

that is absolutely gorgeous! It puts my mini display sump fuge to shame:

That's a very nice looking setup, thank you for sharing!

 

[Fish Styx]

that is absolutely gorgeous! It puts my mini display sump fuge to shame:

Not at all- I love that shallow setup! Hop over to my build thread, share some pics, and tell us more about it.

 

[Fish Styx]

Yes, very cool to look at lol! Thank you for the info! This is very similar to what I'm thinking. I used to have an N. wennerae in his own 10 gallon, he sadly died when the cheap ATO malfunctioned :-(. I very much want another. I'm planning a new tank and hoping to get around 100 pounds of TBS sand and about 50/50 each of their base rock and premium rock. I've got my fingers crossed that a mantis shows up in that order too

But your sand depth and the macros, and maybe even the mangroves are just what I am thinking.

@JoJosReef wants me to write up an article on red mangrove care and displays. I suppose this is the final nudge I needed to actually do it...

 

[Fish Fan]

@JoJosReef wants me to write up an article on red mangrove care and displays. I suppose this is the final nudge I needed to actually do it...

PLEASE DO! I've been interested in Mangroves, but have no idea where to start, other than..... I think they need a deep sand bed lol!

 

[Fish Styx]

PLEASE DO! I've been interested in Mangroves, but have no idea where to start, other than..... I think they need a deep sand bed lol!

I'll try to knock it out this weekend, but may enlist the aid of @danieyella as she is more of an expert than I am.

 

[KrisReef]

Hey all!

When I was dabbling in this hobby sometime about 2003 or so, I remember some reefers on the old RC were trying out Deep Sand Beds (DSB's) 6" deep or greater, or more specifically of interest for me, a Remote Deep Sand Bed (RDSB) for nitrate reduction. Remote, just meaning that the DSB was not in your tank, or necessarily even in your sump. And remote, meaning one could easily control the water flow through it, and take it offline if it goes squirely ;-)

Did this idea go anywhere? Is anyone out there running something like this?

Back then, I believe it was thought that for a RDSB you needed a very, very deep sand bed to see denitrification. Some were experimenting with those wrapping paper storage bins, which are relatively tall and narrow, if i remember correctly.

But now I'm thinking something like a 20 gallon long (or maybe 29) with maybe 6"-8" inches of a very fine sand, topped, in my case, with an inch or so of Tampa Bay Saltwater sand, which I am planning on for my display. The TBS sand is very course/chunky, and can hold the finer sand down, is the idea, not to mention seed some microbes, is the hope, lol!

Water would come in slowly from one short side of the 20L, flowing gently over the sand bed, and exiting the other side of the tank.

My thought was to either manually maintain this sand bed, little by little weekly, and/or pack this area with enough sand sifting/moving critters to keep it well maintained.

Then, the hamster wheel kept turning, and I wondered if I could make this 20L RDSB something of a "macro tank", with the DSB, macro algae, critters, dare I say a Mangrove.....

What do you guys think? Should I go back to 2003 lol??

Thanks for the help!

Are you going to set up a fish tank or a reef?

Mangroves are amazing indoor plants

 

[Fish Fan]

Are you going to set up a fish tank or a reef?

Mangroves are amazing indoor plants

This would be for a 150 mixed reef tank. It's just an idea I've been kicking around for a decade or so lol!

 

[KrisReef]

Should be fine with a remote tank on the system.

I think @Subsea trying to fill in the history gaps of how DSB’s moved on as more and more reefers found their nitrates falling to zero naturally so they began to dose nitrate (and phosphate) for the health of their invertebrates that need them to thrive.

Having a mangrove tree near your tank is beautiful. I saw a huge one at a LFS last week but I didn’t take a picture of the bush

I did shoot the puffer! @AydenLincoln

 

[Fish Fan]

Should be fine with a remote tank on the system.

I think @Subsea trying to fill in the history gaps of how DSB’s moved on as more and more reefers found their nitrates falling to zero naturally so they began to dose nitrate (and phosphate) for the health of their invertebrates that need them to thrive.

Having a mangrove tree near your tank is beautiful. I saw a huge one at a LFS last week but I didn’t take a picture of the bush

I did shoot the puffer! @AydenLincoln

@AydenLincoln - nice puffer!

The mangroves I used to be indifferent to, but more recently I've seen some really nice trees, well trimmed, almost like a large Bonsai tree, and that really appeals to me!

Maybe this is "more than I need" for nitrate reduction as everything is so much more efficient than it was all those years ago. I am planning a large sump packed with live rock (as I've seen other reefers here do), with a dark "cryptic zone".

I originally wanted a typical Chaeto 'fuge, which I've had before, but I've recently had an algae turf scrubber recommended to me. I'm a little on the fence as it's $500, which seems like a lot of money for a 'purple' grow light, some foam, and some plastic where the algae grows, but I guess if it works...

Having a lighted 'fuge separate from my sump appeals to me. If I can add a deep sand bed, macros and mangroves, I think that would be cool. I'll be able to control the flow into and through it, and if it ever goes south I can take if off line entirely.

Does that seem like a plan?

 

[AydenLincoln]

@AydenLincoln - nice puffer!

The mangroves I used to be indifferent to, but more recently I've seen some really nice trees, well trimmed, almost like a large Bonsai tree, and that really appeals to me!

Maybe this is "more than I need" for nitrate reduction as everything is so much more efficient than it was all those years ago. I am planning a large sump packed with live rock (as I've seen other reefers here do), with a dark "cryptic zone".

I originally wanted a typical Chaeto 'fuge, which I've had before, but I've recently had an algae turf scrubber recommended to me. I'm a little on the fence as it's $500, which seems like a lot of money for a 'purple' grow light, some foam, and some plastic where the algae grows, but I guess if it works...

Having a lighted 'fuge separate from my sump appeals to me. If I can add a deep sand bed, macros and mangroves, I think that would be cool. I'll be able to control the flow into and through it, and if it ever goes south I can take if off line entirely.

Does that seem like a plan?

Hewbie says hi and that he loves food!

 

[X-37B]

I ran a remote 30g on my 120 BB and then the 80. 3+" of sand. No3 never went above 2.
Currently running a Deltec nitrate reactor on my ext 170.