A Sediment substrate that works
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NaH2O
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Mineral Galleries - Dolomite
When I searched on dolomite, I kept coming up with use in fertilizers, however, I did not find any information as to the percentage phosphate content.
When I searched on dolomite, I kept coming up with use in fertilizers, however, I did not find any information as to the percentage phosphate content.
Curtswearing
Mantisfreak
Nikki,
I want to know that too. I think that possibly the phosphates would be an issue. On this Comparison of Reactor Medias he found that crushed coral was 10 ppm vs 2 ppm for ARM and 6 from common limestone.
I think since we are using larger particle sizes, melting due to low pH is less likely to be an issue. It will also become unbound from the detritus but will immediately adsorb onto the aragonite in higher pH levels. However, bacteria will still dissolve it off of the substrate and we will have a Phosphate cycle within the substrate.
I guess the question boils down to bacterial growth rates and our limitations of P into our systems. It's quite possible I'm overthinking this and the shedding from the live rock and fish waste would have enough P that it doesn't matter. The Phosphates would adsorb onto the substrate and the bacteria population would immediately grow.
I want to know that too. I think that possibly the phosphates would be an issue. On this Comparison of Reactor Medias he found that crushed coral was 10 ppm vs 2 ppm for ARM and 6 from common limestone.
I think since we are using larger particle sizes, melting due to low pH is less likely to be an issue. It will also become unbound from the detritus but will immediately adsorb onto the aragonite in higher pH levels. However, bacteria will still dissolve it off of the substrate and we will have a Phosphate cycle within the substrate.
I guess the question boils down to bacterial growth rates and our limitations of P into our systems. It's quite possible I'm overthinking this and the shedding from the live rock and fish waste would have enough P that it doesn't matter. The Phosphates would adsorb onto the substrate and the bacteria population would immediately grow.
Ahh good stuff. A P cycle is going to happen with in the bed no matter what, the key to beating that is going to be in keeping the upper zone aerobic, the result will be higher ph and the re binding of P onto seed surfaces, So with our concept I think we have that one beat.
Dave dolomite is very fine and heavy on the magnesium, I believe thier were tests done that showed heavy leeching of magnesium back into the water column screwing up the tanks checmistry. If needed I could search them out for ya.
In the marine biology world Southdown sand would be considered coarse sand, and cc would be considered boulders. So lets look at a few factors.
A southdown bed is going to be 30% water
A cc bed is going to be about 15% water
Relating this to bacterial content, it is going to be about the same, twice as much bacteria in SD then in CC. the nitrification and denitrification rates will also follow suit.
From looking at ARM it looks to be slightly smaller then CC, but not much. Perhaps a mixture of sands would be more aplicable???
Mike
Dave dolomite is very fine and heavy on the magnesium, I believe thier were tests done that showed heavy leeching of magnesium back into the water column screwing up the tanks checmistry. If needed I could search them out for ya.
In the marine biology world Southdown sand would be considered coarse sand, and cc would be considered boulders. So lets look at a few factors.
A southdown bed is going to be 30% water
A cc bed is going to be about 15% water
Relating this to bacterial content, it is going to be about the same, twice as much bacteria in SD then in CC. the nitrification and denitrification rates will also follow suit.
From looking at ARM it looks to be slightly smaller then CC, but not much. Perhaps a mixture of sands would be more aplicable???
Mike
Curtswearing
Mantisfreak
Ok,
If we put the larger crushed coral on top of a layer of finer material, that would keep the top layer aerobic.----good.
We can have a high flow in the tank without sand blowing everywhere----good.
If we put Southdown as the bottom layer, we can support more bacteria----good.
However, this would would be at the lower pH portion of the sandbed so I wonder how much it would melt.----possibly bad.
This is also a very fine material and would possibly clog or fall through the plenum unless we pick a plenum material that is extremely fine.----bad
It's also so fine, that it might be too hard to diffuse through.----possibly bad.
Since our goal is a fairly thin bed, what if we used crushed coral on top and went with a an intermediate size in between Southdown and ARM. We are going to have more bacteria habitat but we are less likely to dissolve or clog IMO.
Southdown is .2 to .5 mm for the most part from what I understand. What if we used 1mm to 2mm under the crushed coral instead of the ARM or Southdown. It seems like a good compromise and also makes picking our plenum material easier.
The original goal of the project was to have a fairly thin layer. We can change the project entirely and go deeper with only crushed coral.
If we put the larger crushed coral on top of a layer of finer material, that would keep the top layer aerobic.----good.
We can have a high flow in the tank without sand blowing everywhere----good.
If we put Southdown as the bottom layer, we can support more bacteria----good.
However, this would would be at the lower pH portion of the sandbed so I wonder how much it would melt.----possibly bad.
This is also a very fine material and would possibly clog or fall through the plenum unless we pick a plenum material that is extremely fine.----bad
It's also so fine, that it might be too hard to diffuse through.----possibly bad.
Since our goal is a fairly thin bed, what if we used crushed coral on top and went with a an intermediate size in between Southdown and ARM. We are going to have more bacteria habitat but we are less likely to dissolve or clog IMO.
Southdown is .2 to .5 mm for the most part from what I understand. What if we used 1mm to 2mm under the crushed coral instead of the ARM or Southdown. It seems like a good compromise and also makes picking our plenum material easier.
The original goal of the project was to have a fairly thin layer. We can change the project entirely and go deeper with only crushed coral.
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good idea...
I think what i'd be looking at using (if I use a single type of material) would be something with the majority size being .5-1mm, with few particles larger than 2mm.
After thinking about it, I also think that if one were to use two different grades of substrate, a fabric or mesh divider between them would not be necessary as long as the more coarse material was on the top layer.
I also have an idea on a variation of the plenum I might try, (but still basically the same) I'll post about it later when I have more time...
MikeS
MikeS
I think what i'd be looking at using (if I use a single type of material) would be something with the majority size being .5-1mm, with few particles larger than 2mm.
After thinking about it, I also think that if one were to use two different grades of substrate, a fabric or mesh divider between them would not be necessary as long as the more coarse material was on the top layer.
I also have an idea on a variation of the plenum I might try, (but still basically the same) I'll post about it later when I have more time...
MikeS
MikeS
The original concept is just to have a sand system that has a better chance for longivity and bioload capability. So what ever the depth needs to be let make is so. Same applies to the grain size. Southdown has a grain size of 0.18 to1.2mm. What I am thinking is that we need it to be slightly larger to allow for better diffusion, I think CC is far to large for what DSB folks want. Remember thier system is still relient on critters for stirring the bed and if we go to large or to small of a grain size they loose that. I know of a sediment that I think might be perfect but dammed if I can remember what it is called. It basically is a touch larger then salt grains. I will look for it over the weekend.
mike
mike
the caribsea oolite aragonite I use in my DSB is about that size (salt)...there are however a lot of fines...
I'm thinking I could take this substrate to the road materials lab where I work, dry it back, do a seive gradation on it and screen out both the fines and larger pieces of shells and such. I realize however not everybody has access to the equipment to do this as I do, so that's not a practical solution for most....
MikeS
I'm thinking I could take this substrate to the road materials lab where I work, dry it back, do a seive gradation on it and screen out both the fines and larger pieces of shells and such. I realize however not everybody has access to the equipment to do this as I do, so that's not a practical solution for most....
MikeS
I have a email into a buddy that works for a substraight company, I am going to see if I can get some info on particle size and make up from him. They have a ton of substraights for both aquariums and other stuff, so I will see if I can get something cooking from that way to.
Mike
Mike
NaH2O
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Sounds good Mike! I'm interested to see what you come up with. In regards to the anaerobic zone....how deep does the substrate need to be in order to create an effective anaerobic zone? I remember some time ago, the depth of DSB went from 4-6 inches to 2-4" and still was effective at denitrification? The downfall was the fact that the bed filled up faster. Since we don't have to worry about the eventual fill up, then we would be fine doing the 2 inches? Eeeek - I may have the depth thing wrong, so please correct me if that is the case.
NaH2O said:
Good point...
Personally, I don't think it will be as much of an issue with this system as it is with a DSB. The work done by the little tunneling worms and critters that aids in diffusion thru the substrate will in a large part be done mechanically by the removal of water through the plenum. As for the rest, I'm going to hazard a guess and say if the tank has enough live rock the detrivore issue will not be as big of a problem.
Ok...sorry to backtrack a bit, but this idea hit me just recently...I've got an idea for a variation on the plenum. Basically, it is the same, but a single collection tube in the middle, running lengthwise instead of front to back. However the tube will have a Tee in the middle, with a tube running from it to the back of the tank. That way there will be no tube running up the side of the tank like in earlier lengthwise drawings. In addtion, I think that a Tee in the middle of the collection pipe will aid in extraction...the amount of pull at the far ends of the collection tube will be greater than if you were simply pulling from one end...
my crude drawing is a top view of the plumbing alone...
Maxx
Staff Housemonkey
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Sorry for backtracking a bit, for some reason I wasnt getting replies to this thread, and naturally, my life has gotten exponentially busier in the last couple of days.....sigh...just 4 more weeks at the police academy, (6 finals though, DOH!)
Anyway.....
I think we're all trying to get to a pro DSB standpoint, or at least a DSB that works for us. The detritus I'm talking about removing shouldnt be so big as to clog the system. Remeber, in order to get to where it can be removed, it has to pass through the substrate in order to get to the plumbing. Monster pieces of detritus arent going to be able to do that, they will get siphoned up from the top layer of substrate.
Am I wrong here???
Just some thoughts......good work everybody.
Nick
Anyway.....
Agreed.
MikeS,
I think we're all trying to get to a pro DSB standpoint, or at least a DSB that works for us. The detritus I'm talking about removing shouldnt be so big as to clog the system. Remeber, in order to get to where it can be removed, it has to pass through the substrate in order to get to the plumbing. Monster pieces of detritus arent going to be able to do that, they will get siphoned up from the top layer of substrate.
This is exactly what I thinking.
Curt, I have a 50lb bag of ARM that I bought for my reactor, here at the house...you're more than welcome to come by and see it or photograph it if you like. One concern about arm though is the PH. One ARM's major selling points is that it dissolves at a higher PH, so that the difference between the PH of your tank and the Calcium reactor effluent is less than when using other media. So now we have a substrate that will dissolve ina a PH of 7, sitting partially in an area w/ a PH of 6 or less......thats one way to get detritus thats trapped in the substrate out........(No)
I thought that if you mixed two different sizes of subsrtates that the smaller of the two wound up on top of the larger over a period of time, due to gravity, the size difference, (smaller able to move/shift between or thru the larger, critter displacement etc.)???
Am I wrong here???
Just some thoughts......good work everybody.
Nick
Ok mojo...sorry to be the slowpoke on the plenum....
The large outside diagram is the view looking from the side of the tank. "front" represents the front of the tank, "back" represents the back of the tank. The smaller green inset is a view from the top of the tank. The blue arrows represent flow through the plenum.
again, sorry to backtrack...just throwing out an idea...
MikeS
The large outside diagram is the view looking from the side of the tank. "front" represents the front of the tank, "back" represents the back of the tank. The smaller green inset is a view from the top of the tank. The blue arrows represent flow through the plenum.
again, sorry to backtrack...just throwing out an idea...
MikeS
Witfull
Well-known member
that would help in the draw. but water being water, threre wouldnt be even pull from both sides, but if enough pull is applied the nasties will be removed. the question is how much water will be pulled out of the system to facilitate the suction.
kylem
A piece of the Reef!
Why don't you just use a Sea Cucumber or two...They do the same thing and dig in the sand. Nature usual has the best solutions. In the wild blue there are no plenums so how does it happen in real out on a reef....getting rid of detrius and the like.
