Quote:
Originally posted by MINIATUS
...but this time I'm going with a DSB using South Down. Question is will 5 inchs be any more beneficial than 4 inch.
|
You will get a large number of opinions on this both ways. If you are going to a DSB, prolly need to have at least 5 inches, better at 6 inches, but not necessarily what you may get feedback for.
In a substrate system, either it will need to be very shallow such that it wil remain aerobic and can be siphoned and cleaned: or very deep and quite capable of establishing anaerobic zones early into the maturing process of the DSB. I originally thought that possibly a good compromise would be 3 inches or so, but that is turning out to not be the case, as these intermediate depth systems really just turn out to be nitrate factories that fuel benthic sulfate reduction in the depths of the DSB, many times in areas near the surface but lacking current (as under LR placed on the
sand beds). I spent a lot of time on the net and on the phone speaking with folks that had failures at 1 to 3 years, and although many of them started off with 4 or so inches, most of these systems lost a good portion of their aragonite to the water column with slow dissolution to the point that they were no longer 4+ inches, but somewhere in the 2 to 4 inch range. Many of these systems
lacked (or experienced as may be indicated) one of any of the following:
- adequate depth to start with
- adequate maintenance of that depth (gradual slow dissolution of the aragonite)
- adequate current across the sand bed
- appropriate granule size (many people still using very large substrates or mixes of too large and appropriate diameter particulates)
- adequate (usually infrequent) or total lack of water changes
- adequate access to current (liverock compressing sand)
- experienced inappropriate disturbances of the SB (either physical stirring/vaccuuming or sand bed critters)
- sand bed maturity
- sand bed benthos diversity
- experienced heavy bioload in tank
- used bioballs (and resulting high water column nitrates)
- experienced heavy feeding (contrary to the popular myth) resulting in high phosphates
- experienced TRACE ELEMENT SUPPLEMENTATION
- additional system of nitrate/phosphate export (clumped together here were skimmerless systems and no refugia)
- experienced, interestingly enough, CO2/Ca-reactor use, although this may be the same as saying that these systems also used saltwater...
- experienced poor water change scheduling (or none at all)
This is by no means a complete list, and is still statistically inadequate, but these are the things that stand out so far.
I am doing a number of interviews and will prolly start sending out very specific questionnaires to folks that I find still have DSBs and are having success, as well as those of you that would volunteer to be frank that have one or more failures with your sand beds. The sample size now is small, (7 that I can use, 2 that the interview was not substantiated with the samples that were sent), but these are the trends that stand out so far. Once I have collected info from an adequate number of systems to see clear cut trends, I will post the results (or publish, not sure which at this point).
I will continue to use DSB's, as I still feel that much of the rational behind pulling the systems is based on open system dynamics that may not apply to alo cases in closed static systems. Entire food chains are missing in our systems, as well as the truely deep sink available to the oceanic cycling of nutrients (unless Spanky gets his closed system hydrogeological petroleum and diamond making machinery going...
) among many other things we lack in a closed system. If we supply the right husbandry skills and methodology to DSB's, they can be made to work and apply their natural appearance to the system (along with their many benefits to closed systems), albeit the possibility of a limited duratiion depending on how well the maintenance is carried out.
I guarantee this will be a thread full of opinions and many diverse POV's.
Good luck in sorting out the wheat from the chaffe.
"I'm holding on to this fish poop with both hands, and I'm not letting go!!!"
