krux
Member
i do not type very fast, so i am not going to transcribe for everyone the two articles touching on this in the current issue of fama (july) but one is written by bob goemans who writes the monthly article "sand mail" which deals with bsb, plenum, and other sand oriented filtration. the second is written by dr. charles matthews who writes the monthly column "reef science". the articles can be found on page 52 and 128 respectively.
goemans writes
"research has shown that anaerobic areas generate an ample supply of ammonium, which is the favorite algae nutrient. remember, nitrate is only reduced to ammonium, no further in anaerobic areas. yes nitrate is reduced and when the bulk water is tested, low nitrate levels appear to be under control because of the denitrification process in deep sand and inside rock. but that can be somewhat misleading because in anaerobic areas, nitrate is only reduced to ammonium (a nitrogen compound), no further. Fact not fiction! however in anoxic areas, nitrate is completely broken down/oxidized. therefore, anything over an inch or two of sand and/or the overabundance of live rock is the perfect breeding ground for the ideal algal nutrient, and this production of ammonium is not visible on our test kits, so the average aquarist doesn't see it. but the formation of algae in the aquarium is in part a result of this ammonium production, as algae is the pyysical incorporation of nitrogen compound! many aquarists also fail to adequately control phosphate. so it should be clear that minimizing anaerobic areas in the aquarium and the on-going control form the start of the aquarium where phosphate is concerned, is essential in preventing unwanted algae somewhere down the line"
he goes on to talk about phosphate removal techniques, but this is in effect the chemistry behind why hair algae will break out, even in an established (some times very established tank) without some sort of phosphate intervention. this also explains the collection and saturation of ammonium in aquariums. this can easily be battled with a refugium with aggressive harvesting and nutrient export, but that is another topic which is unfortunately usually never discussed as going had in had with dsb's.
so there is the source of algae and phosphate/ammonium tank crashes.
matthews discusses the topic of dsb's and filter feeders and the build up of bacterial toxicity (another cause of crashes).
he cites that "a rigid, coarse diversity poor sand bed in a nutrient rich environment will support insufficient grazers of bacteria to prevent bacterial toxicity defenses from being triggered during growth, leading to subtle toxic tank syndrome. But there are significant limitations in our present ability to keep organisims - particularly, consumers of particulates in mass quantities, of which dendronephthyla is a poster child, but including bivalves, crinoids, and essentially all non-photosynthetic organisms, which typically are so brightly colored - andi believe it is possible that the sand bed itself is the limiting factor. substrates in the ocean are, typically, exactly graded and matched to the flow regime in which they are found. the flow regime is almost enough to lift the substrate; this allows the substrate to settle out. the invertibrates that live in a particular regime are not only adapted to the size of the substrate, but to oxygen gradient related to the overlying water flow as well."
he is in effect stating that no matter how much you pay for your fancy southdown, or how far you drive for yardright, unless you miraculously grade the sand to the exact specifications that it would occur naturally, in the exact same water flow patterns as it would occur naturally, and introduce the exact species of infauna and bacteria, you will NOT be recreating the "natural" method that so many feel that they are creating with the dsb method.
there have been a number of other articles in various publications recently talkinga bout the same issues.
it all comes down to the same thing that i have been suggesting over and over in many threads concerning the construction of a dsb, the maintenance of a dsb, the lack of a dsb... this board is a huge wagon that a lot of sucessful reefers have jumped on over the years, and it is sometimes dangerous to voice an opinion out of fear of sounding different, or contradictory. i challenge folks to find proof for their arguments, or at least have the formal training to know what they are talking about. just because you might have gotten the sand bed setup right in your tank, and just because you have 17 friends whose tanks all seem to work, does not mean that any one method is bulletproof. how your setup works will be drastically different from mine, and so it shall be with everyones' tanks.
so yes that is why i argue every time someone asks about filtration and immediately a dozen people say that a dsb is the only way to go. yes if done properly, folks have had success, but folks are still having success with undergravel filters, there are beautiful tanks running bio-balls which most people here wish were never invented, there is great luck with refugiums, algal turf scrubbers, denitrification reactors... there are a lot of methods of working out the chemistry involved.
so for you who bought 300 lbs of southdown, asdded a closed loop system or wavemaker, added an infauna kit, and were sucessful, GREAT! but please do not shut the book on emerging research, and emerging technology because you have seen what is in most cases fairly short term results (hats off to the 15 year dsb folks). it was not long ago that folks saw the dsb as a miracle cure and trend... now that research is coming out by respected aquarists and authors, some of them very professional and not at all amateurs, it is time to maybe look at the drawbacks that are inherent in any setup that tries to recreate an impossibly complex and diverse microcosm.
further research might prove that there will never be a better system than the dsb, but that is the FUTURE, are all yall a bunch of powerball gamers? i am not, i would love to have the chance to save my reef before it crashes by simply taking the time to research, and listen to exterior opinions.
and thanks to mn for keeping folks on their toes
goemans writes
"research has shown that anaerobic areas generate an ample supply of ammonium, which is the favorite algae nutrient. remember, nitrate is only reduced to ammonium, no further in anaerobic areas. yes nitrate is reduced and when the bulk water is tested, low nitrate levels appear to be under control because of the denitrification process in deep sand and inside rock. but that can be somewhat misleading because in anaerobic areas, nitrate is only reduced to ammonium (a nitrogen compound), no further. Fact not fiction! however in anoxic areas, nitrate is completely broken down/oxidized. therefore, anything over an inch or two of sand and/or the overabundance of live rock is the perfect breeding ground for the ideal algal nutrient, and this production of ammonium is not visible on our test kits, so the average aquarist doesn't see it. but the formation of algae in the aquarium is in part a result of this ammonium production, as algae is the pyysical incorporation of nitrogen compound! many aquarists also fail to adequately control phosphate. so it should be clear that minimizing anaerobic areas in the aquarium and the on-going control form the start of the aquarium where phosphate is concerned, is essential in preventing unwanted algae somewhere down the line"
he goes on to talk about phosphate removal techniques, but this is in effect the chemistry behind why hair algae will break out, even in an established (some times very established tank) without some sort of phosphate intervention. this also explains the collection and saturation of ammonium in aquariums. this can easily be battled with a refugium with aggressive harvesting and nutrient export, but that is another topic which is unfortunately usually never discussed as going had in had with dsb's.
so there is the source of algae and phosphate/ammonium tank crashes.
matthews discusses the topic of dsb's and filter feeders and the build up of bacterial toxicity (another cause of crashes).
he cites that "a rigid, coarse diversity poor sand bed in a nutrient rich environment will support insufficient grazers of bacteria to prevent bacterial toxicity defenses from being triggered during growth, leading to subtle toxic tank syndrome. But there are significant limitations in our present ability to keep organisims - particularly, consumers of particulates in mass quantities, of which dendronephthyla is a poster child, but including bivalves, crinoids, and essentially all non-photosynthetic organisms, which typically are so brightly colored - andi believe it is possible that the sand bed itself is the limiting factor. substrates in the ocean are, typically, exactly graded and matched to the flow regime in which they are found. the flow regime is almost enough to lift the substrate; this allows the substrate to settle out. the invertibrates that live in a particular regime are not only adapted to the size of the substrate, but to oxygen gradient related to the overlying water flow as well."
he is in effect stating that no matter how much you pay for your fancy southdown, or how far you drive for yardright, unless you miraculously grade the sand to the exact specifications that it would occur naturally, in the exact same water flow patterns as it would occur naturally, and introduce the exact species of infauna and bacteria, you will NOT be recreating the "natural" method that so many feel that they are creating with the dsb method.
there have been a number of other articles in various publications recently talkinga bout the same issues.
it all comes down to the same thing that i have been suggesting over and over in many threads concerning the construction of a dsb, the maintenance of a dsb, the lack of a dsb... this board is a huge wagon that a lot of sucessful reefers have jumped on over the years, and it is sometimes dangerous to voice an opinion out of fear of sounding different, or contradictory. i challenge folks to find proof for their arguments, or at least have the formal training to know what they are talking about. just because you might have gotten the sand bed setup right in your tank, and just because you have 17 friends whose tanks all seem to work, does not mean that any one method is bulletproof. how your setup works will be drastically different from mine, and so it shall be with everyones' tanks.
so yes that is why i argue every time someone asks about filtration and immediately a dozen people say that a dsb is the only way to go. yes if done properly, folks have had success, but folks are still having success with undergravel filters, there are beautiful tanks running bio-balls which most people here wish were never invented, there is great luck with refugiums, algal turf scrubbers, denitrification reactors... there are a lot of methods of working out the chemistry involved.
so for you who bought 300 lbs of southdown, asdded a closed loop system or wavemaker, added an infauna kit, and were sucessful, GREAT! but please do not shut the book on emerging research, and emerging technology because you have seen what is in most cases fairly short term results (hats off to the 15 year dsb folks). it was not long ago that folks saw the dsb as a miracle cure and trend... now that research is coming out by respected aquarists and authors, some of them very professional and not at all amateurs, it is time to maybe look at the drawbacks that are inherent in any setup that tries to recreate an impossibly complex and diverse microcosm.
further research might prove that there will never be a better system than the dsb, but that is the FUTURE, are all yall a bunch of powerball gamers? i am not, i would love to have the chance to save my reef before it crashes by simply taking the time to research, and listen to exterior opinions.
and thanks to mn for keeping folks on their toes
