DSB - down through or upwelling

[dnjan]

It is so much easier to just remove all the detritus before it ever needs anymore processing that the LR & skimmer misses, way too easy. JMO

But hard to automate ...

 

[Scooterman]

The way my tank is designed you don't need much to accomplish this, husbandry is way much less.

 

[dnjan]

How often do you need to clean out the detritus-catcher?

 

[Scooterman]

Whatever detritus that is left settles in an area in the sump, depending on the amount made determines how often I would need to suck it out, usually when I do water changes so basically no time is used to remove it. It isn't required to automate detritus removal but processing it in the plenum still has husbandry requirements, not to mention this design can lead to possible problems over time.

 

[dnjan]

The trick with that method of detritus collection is to have a high-enough flow rate in the tank and overflow system to keep the detritus in suspension and removed in a timely manner, combined with a low-enough flow rate in at least one chamber of the sump to allow it all to settle.

Or have you set up a cyclone-type separater?

 

[aquariumdebacle]

What I really want to accomplish is some increased functionality of the sand-bed. I will have two seperate plenums seperated by a six-inch gap in between that will not be serviced by the plenum. animals that need to dig deep into the sand such as anenomes and burrowing clams can utilize this area. I would microfilter the water before putting it in the plenum. I would really like to see if it is possible to prevent an accumulation of detritus in the sand bed as this seems to be the fatal flaw and the reason they eventually have to be replaced.

 

[Scooterman]

Dan can you sketch up what you have in mind? It would be nice to see what your trying to do & how you would go about doing it, I remember where Mike made a flush Plenum where he had a drain at the bottom that he would open up & flush that anaerobic area out.

 

[Tantricreef]

Very interesting, I would think an up flow would totally defeat the system and just turn it into an undergravel filter, with flow channels etc. Micro filtering the water would deprive the dsb of the nutritional source required to "do the job", over time the bed becomes less active as the anerobic content drives off critterage, basically its a septic field and like any septic field its got to be rebuilt every so often.:lol: just my thoughts and absolutly not a defendable position, any type of betterment for water quality is worth exploring

 

[aquariumdebacle]

Yes, I agree entirely. What I am concerned with is maximizing nitrate reduction because I think this is the strength of a DSB. The traditional problem has been accumulation of organics. I won't turn it into a undergravel or reverse flow system just by the fact that I am considering a flow rate that will keep the bed anaerobic.

The reason for microfiltering is that you need to prevent clogging of the .10 mm mesh screen that I need to hold back the oolitic sand that I all ready have. microfiltering on the micron scale would not deprive the bacteria of the nitrate nutriens they need as it would easily pass through such a course mesh.

As far as critterage goes I have plenty of recesses for them in the system. What I specifically am attempting to address in the sand bed is the nitrate ion as I will produce an excess with the trickle filter which I refuse to eliminate.

I realy appreciate the comments here because it causes me to further think about my ultimate goals. At the moment, I am leaning towards a seagrass bed heavily populated with fish.

Any and all comments are truly appreciated because this is an area that has not been thoroughly explored.

 

[salty joe]

quote "The reason for microfiltering is that you need to prevent clogging of the .10 mm mesh screen that I need to hold back the oolitic sand that I all ready have."


Have you considered the clogging tendencies of bio-films?

 

[aquariumdebacle]

Yes, I have considered bio-film build up to be a major issue. I believe the monthly or quarterly flushing will minimize this issue. I am considering the slow flow to prevent any quick build up problems.

 

[Tantricreef]

Dan, have you thought about a denite coil ? removal of suspended matter is obtainable so why not just address the nitrate??

 

[aquariumdebacle]

I am considering a nitrate coil for the input in an upwelling scenario. The DSB is part of the system as a whole. I am looking to have a seagrass bed in the sandbed and I want to maximize the bed's capabilities. I am still undecided about the direction That the water will flow. Up or down? Iam still undecided!

 

[dnjan]

I would think that the seagrass bed would go a long way towards removing the organics from the sandbed.

Question - will you need to allow for some amount of organic buildup in the sand before the seagrass can establish well?

 

[aquariumdebacle]

I shouldn't need any time for a buildup as the sand was/is active for two years; one of which it had a heavy load. From my understanding the best success for seagrsses is to have a little soil a with it in a plug. This will be the most difficult task to find a good source of seagrass. I don't think that the seagrass itself will absorb a significant amount of nutriens from the bed. They will possibly absord some from the water column but the root structure does not remove a significant amount of organics.

 

[Tantricreef]

The seagrass is in the dsb? if so an upflow would/could work IF you can anchor the seagrass.Had a thought, what about suspending a growth media area something like hydroponics,maybe marbles for media so no clogging, with a 1 or 2 inch dead space above the dsb

 

[aquariumdebacle]

drawing of the plenum

Here is an idea of what I am trying to do. I waited a while for the picture because I am a lazy Irishman but I also wanted some ideas that were not influenced by a visual representation to give me more ideas. So now here is the visual representation with the two sides showing the direction of water flow. One side is the upwelling through the sandbed and the other side is the pull-down through the sand bed. I do plan to have the capability to do both on different sides.