shandy_say
New member
Thanks! Those are really possible! What can you say about adding some hermits/detrivores in the fuge area to clean it up? Would this be ok?
Removing DSB Fuge
- Thread starter shandy_say
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epstein
New member
Ummm I removed mine 5 mos ago and never saw a rise in anything substantial. I shut off tank and used my trusty shop vac. I then rinsed the chamber and vac that out. then refilled and only allowed my carbon and phosban reactor to circulate and filter. When that was done I fired her up and used a filter sock for 2 days then did a 20 gal water change... No increase in everything. took me about 3 hrs from start to finish.
Kolognekoral
New member
Ruprecht,
I would have to disagree with you on this. In a typical aquarium, most of the denitrification is aerobic, even with a DSB. It is happening in the water column, on the rocks and in the top layer of the DSB. The anaerobic processes are not as big a role player as often thought, although they are certainly at work and the main reason to have a DSB.
I think you have hit an important point, in 'why remove the DSB'. In a VSV/Zeo type system, a DSB can be counter productive, as the carbon dosing strips the water of nutrients faster that they can seep into the DSB and feed it. Although the two types of waste removal are similar, they work on very different time scales and working biomass. In short, one may not even need the DSB, as the carbon dosing is efficient enough to produce the required results. Ultimately, one mush decide what one wishes to have. As to substituing live rock, the result will not be the same as a DSB, that is clear, but it presents a viable use of the space for raising copepods, etc.
For myself, although I like my DSB, I am in the process of reducing it, as it seems to be having problems on the anaerobic side in conjunction with carbon dosing, long term. I may change the DSB area into a cryptic refugium.
ciao,
Jamie
In my opinion (and it's just that, an opinion) surface particulate detritivores such as brittle stars and snails would be the easiest and least invasive. Google the subject to find out more information.
Anaerobic in my case implied anoxic, or very low levels of oxygen. Anoxia can only occur in the lower levels of a DSB (or plenum) or the deep interiors of some types of live rock. To say that "most" denitrification occurs where oxygen is most abundant (sorry but I have to say) is patently false. Most is in itself inaccurate, 51% is most, so is 99%. Denitrification, the conversion of nitrates (NOˉ3) into nitrogen (N²) occurs most easily when oxygen is depleted. This is not the case in any of the places you have mentioned. Maybe in a oxygenated sulfur reactor with a specific monoculture of aerobic bacteria can denitrification occur, but I have to disagree with you as well. Nitrification on the other hand is abundant in all the places you mentioned, because turning ammonia into nitrite(NOˉ2) and nitrate(NOˉ3) is an oxidative process.
Kolognekoral
New member
Ruprecht,
I follow what you are saying, but, as I put it, in an aquarium, this simply doesn't happen. The oxygen levels are pushing the nitrification processes and there is very little product left for classic anaerobic bacteria. I find this is supported by the fact that, again, in an aquarium, when we remove a DSB, we rarely see a jump in nitrogen products, as long as the rest of the system is intact. Other established bacteria are continuing the cycle.
As far as an ocean reef is concerned, 90% of the process is caried out via aerobic bacteria and phytoplankton, which directly assimilate the nitrogen. Anaerobic bacteria still play a minor role.
We can agree to disagree on this.
I follow what you are saying, but, as I put it, in an aquarium, this simply doesn't happen. The oxygen levels are pushing the nitrification processes and there is very little product left for classic anaerobic bacteria. I find this is supported by the fact that, again, in an aquarium, when we remove a DSB, we rarely see a jump in nitrogen products, as long as the rest of the system is intact. Other established bacteria are continuing the cycle.
As far as an ocean reef is concerned, 90% of the process is caried out via aerobic bacteria and phytoplankton, which directly assimilate the nitrogen. Anaerobic bacteria still play a minor role.
We can agree to disagree on this.
elegance coral
They call me EC
Can you post a link to support this idea?
In systems where the removal of a sand bed does not increase nitrogen products, there may be many contributing factors. This alone does not indicate that aerobic bacteria are removing nitrate.
Kolognekoral
New member
Elegence,
i can't find the articles related to this, as this was over a year ago, but it may have been on Advanced Aquarist or it may have been from a German forum/publication. It was essentially a discussion on the processes in a DSB and the data showed that DSBs, although capable in theory to reduce the NO3 further, as well as PO4, rarely showed this effect. Aerobic processes were simply outcompeting, as they are favoured by aquarium husbandry. This makes sense, as the complete reduction of nitrates is not actually the end desired, rather the removal of nitrate products (as well as PO4), which was more likely to happen through skimming and phytoplankton/algae uptake. Essentailly, the DSB doesn't fully mature and reach its possible potential. I suspect we may get other results, if the test tank had no other nutrient export. This was done in the past, which probably led to the assumtion that reduction always takes place in a DSB, but the current trend it to multiple waste removal systems, and these often compete with each other. As the aquarist really wants low nutrients, and is getting it with multisystem waste reduction, no one complains.
As to other anaerobic systems being in play, certainly possible, but we cannot ignore the fact that nature chooses the easier path, when possible. If aerobic conditions fill the bill and are faster in assimilating the nutrients, then anaerobic conditions are not required and may be starved out. This may well connect to the often reported collapse of DSBs. Their nutrient supplies are cut off or drastically reduced.
In the end, there are many factors at play, but to think that a DSB will always perform within cetain parameters is simply ignoring all the possible factors.
Actually, this does indicate that the aerobic bacteria are capable of out competing the anerobic bacteria and, yes, there are aerobic bacteria (Pseudomonas, Paracoccus) that can completely assimilate nitrates! Who/what made you believe otherwise? Typically, phytoassimilation removes most NO3 compounds directly, as this is the basis of their nutrition, another competitor with the anaerobic bacteria. We have a food source with many takers. Plants reduce the nitrates and release oxygen very effectively.
Does this explain what I'm purporting?
shandy_say
New member
Thanks for the info guys! This is again turning out to be a very useful discussion on the use of dsb's in a fuge. Now this brings another question to my mind, does the denitrifying bacteria in the dsb need po4 to remove nitrates?
Kolognekoral
New member
The relationship is reverse: to assimilate Phosphorous, Nitrogen is required. One of the reasons we often see 0 nitrates, with rising phosphates. As the reverse is known to happen, it would seem the bacterial strains involved are not the best for NO3 reduction, or the DSB is simply not funtioning properly/fully. There are still a few open questions. Unfortunately, there are no test kits for many of the possible parameters we could monitor.
In marine systems, there is a phosphate cycle and a nitrogen cycle. They do not directly interact, however, the phosphate cycle is dependant on nitrogen. As we have various versions of DSBs in use; some with lighting, some with algae, some in complete darkeness, some in the reeftank, instead of the refugium. A controlled comparison may tell us a great deal more. I suspect a dark DSB would be able to complete both P and N cycles, once it has matured, but most tanks have a competitive 'other', that makes this difficult or impossible. Then there is the question of bio-load. How far can one push it?
In marine systems, there is a phosphate cycle and a nitrogen cycle. They do not directly interact, however, the phosphate cycle is dependant on nitrogen. As we have various versions of DSBs in use; some with lighting, some with algae, some in complete darkeness, some in the reeftank, instead of the refugium. A controlled comparison may tell us a great deal more. I suspect a dark DSB would be able to complete both P and N cycles, once it has matured, but most tanks have a competitive 'other', that makes this difficult or impossible. Then there is the question of bio-load. How far can one push it?
elegance coral
They call me EC
Yes. All living cells require phosphate. It is essential for life as we know it. No phosphate, no denitrifying bacteria, and no reduction in nitrates. There is phosphate in every healthy reef tank though. Even if we can't detect it with our test kits. In most systems, we don't need to worry about a shortage of phosphate.
shandy_say
New member
Bioload in my tank is pretty average in my opinion. I only have 6 fishes in my tank and 5 of them are small fishes. I only have 1 tang in my tank and he his just about 5 inches. Now im still having a problem with nitrates although all my LS even my SPS are thriving im still having a hard time getting them to color up because of the 10-20ppm nitrates. The thing with carbon dosing is that it does not work properly as my phosphates are way too low. So now im pretty stumped as to what else i can do to bring down the nitrates. Already shut off my phosban reactor but still no reduction in nitrates. Also doing daily dosing of mb7 and vodka yet i still can't see any difference. I also feed less now. My last option is to do a massive water change maybe about 70% but that is just a short term remedy in my opinion. Any other ideas?
Yes im sure there is still some amount of phosphate in my tank but my concern is that it is way too low for carbon dosing to work properly. I don't know what else to do.
elegance coral
They call me EC
I don't think your tank is as low in phosphate as you suspect. You're harvesting chaeto every month, algae is growing wild in your frag tank, and you have detritus accumulating on the surface of your sand. There is plenty of phosphate in the system. Regardless of what the test kit shows.
Your tank is still young. At 7 months, it's basically just going through puberty. Especially with a 4 month old DSB. It's very common to have algae, nitrate, and phosphate issues at this stage.
Can you post pic's of your system so we can see how it's set up? Contrary to what you are being told in this thread, you will not see nitrate reduction from oxygen rich environments in the system. This is why we did away with bioballs in reef tanks. If you eliminate high oxygen environments where bacteria can colonize, but can't create an anaerobic environment, like bioballs, reef rubble, sponge filters, and pads, it will help to keep nitrate under control. Designing the system, or maintaining it in a way that limits detritus accumulation will also help manage nitrates.
Here are a few articles on DSB's and ethanol dosing.
http://reefkeeping.com/issues/2004-10/eb/index.php
http://reefkeeping.com/issues/2004-11/eb/feature/index.php
http://www.ronshimek.com/deep_sand_beds.html
http://reefkeeping.com/issues/2004-10/eb/index.php
http://reefkeeping.com/issues/2004-11/eb/feature/index.php
http://www.ronshimek.com/deep_sand_beds.html
Exactly, phosphate is being assimilated as soon as it is being produced. You just have excess nitrate in your tank.
Try to get only the exit from your skimmer into your DSB/Fuge, thereby limiting particulates. Do water changes for a few weeks to draw out the nitrate from your rocks, leave the phos reactor off, and maybe even siphon off the particulate from the surface your DSB and maximize flow over the sand.
Things should improve in a few weeks leaving your system in much better balance.
shandy_say
New member
I do have some filtersocks and filterfloss that i use to keep the water clear. Maybe I do need to remove those...hmmm.....I do wash them every week though.
As for the cheato, although i prune it 1x a month, i only remove a little because it doesn't really grow as much.
Here is a pic of how my sump tank is setup...Pics were taken during the 1st few months...I haven't gotten around to taking new pics of my sump setup...
Cheato is located on top of the LR under the light.
shandy_say
New member
The exit from my skimmer goes directly over the dsb/fuge. Im planning to siphon out the detritus in the fuge over the weekend. Hopefully that will help bring down nitrates.
shandy_say
New member
hmmmm......maybe I should just move the LR into the in-line frag tank to convert into an in-line LR fuge and then just leave some cheato in the dsb fuge. What do you think?
Right now im running into another problem! One by one my rics are disappearing! They have been there since the beginning and now that ive been dosing mb7 and vodka...they are disappearing one by one. Any ideas why?
Right now im running into another problem! One by one my rics are disappearing! They have been there since the beginning and now that ive been dosing mb7 and vodka...they are disappearing one by one. Any ideas why?
LOL
Sorry, that's funny. Tragic, but funny. My bad.
You may have a shrimp/crab or a very large worm. Either way, that could be responsible for elevated nitrate. Everybody poops afterall. Probably a worm, they can grow fast if they get enough food, which it sounds like it has.
