high nitrate levels cont.

[Gealcath]

The Ocean doesnt use denitrificators so there is no reason to use something that gets the same result as a DSB. All a denitrification reactor does is creates a low oxygen enviornment for Aenerobic bacteria to grow. A DSB creates the same situation, as was previously mentioned since Aenerobic bacteria live in oxygen poor enviornment, they take the Oxygen from Nitrates which then creates harmless Nitrogen Gas completing the Nitrogen Cycle. Aenerobic bacteria also will live int he pores and crevices of rocks.


For just a closed aquarium system a denitrator is REALLY an expense not needed, and the more mechanical filtration and outside gadgets needed, you gradually make a more artifical enviornment then a natural one (The ideal of aquarium keeping is to reproduce the same processes that happen in nature rather then use outside equipment to do it for you)

 

[kraig m.]

Actually that helps out alot. I think I understand. In order for the nitrates to deplete from the system you have to have a place with low O2 content. See I think I got it now. So you have to have both aerobic and aenerobic bacteria in a tank. So the good water flow that you have above the DSB can be the high O2(aerobic bacteria) place, and below in the DSB is where all your anerobic bacteria grows to control the nitrate, that way there's always a continuous cycle. That is where I was having the most trouble is understanding the basic concepts of the nitrogen cycle. I beleive you have cleared that up for me. One more thing. Since I need to add a DSB to the tank and I know it suppose to be deep, how much sand can I add to it at a time without hurting the fish I have in the tank? And I beleive I asked this before, but which sand will be best to use over the crushed coral? Should I use a real fine live sand or will sand that is a little coarse be ok? You would think the finer the sand less deep the bed would have to be, in order to get no O2 down there, in order for the anaerobic bacteria to thrive. Thanks for all the help. I have learned alot. I forgot to add something again I do it every time. When I do water changes I vacuum the gravel bed. Should I quit doing this? I know when I make the DSB I shouldn't vacuum it. That would just disturb the anaerobic bacteria, wouldn't it? So until I get the DSB should I just leave the sand bed alone? When I do vacuum it there's alot of stuff coming out of the bed. It's real cloudy looking. I thought I was removing the nitrates. I have heard several times to leave a sand bed alone, to not touch it. I never knew why.
kraig m.

 

[Gealcath]

The smaller the grain size of the sand the better, because it creates more surface area for bacteria to colonize. If you have a good cleanup crew you shouldnt have to vaccum the substrate because everything stays ontop of the sand bed, which will eventually get eaten by the cleanup crew (remember everything on a reef is food for something else, even waste products). However the thing about not disturbing a sand bed is mostly due to possible Anoxic (As in 0 Oxygen present) areas that can "possibly" develop (usually by having a DSB thats too deep or that doesnt get sifted well enough). Since a Anoxic area is devoid of any Oxygen, nothing can survive in there not even bacteria, so stuff that decays tends to produce toxic gases like Sulfphur type gasses that have the "rotten egg" smell.


Although thats something that VERY rariliy happens, since even with a 3-4" DSB and good water flow it usually stays oxygenated enough where its not a worry. Also a sudden rush of Oxygenated water will kill the Aenerobic bacteria you want so its another reason to not disturb it too much.

 

[Dale W.]

At this point until you get the DSB established, you should still vacuum the detritus from the bottom. After you get the bed going you will no longer need to do this eccept an ocasional surface cleaning to rid the sand of the setimant.

A clean up crew is a good thing to have but you will have to be selective on what you put in there. Since you have a puffer, most crabs, hermit crabs and crustations will be out. They are a favorite food for these guys.

As far as grain size goes, well, the finer sand is better but again, with the fish that you have, the sand will more than likely get stirred up a bit. The grain size isnt so much for surface area for colonization but more for density to creat anaerobic areas in a shallower depth.

Anaerobic is defined as "without oxygen" These are bacterial forms that can survive in no oxygen areas and depending on the strain will actually die off if subjected to oxygen. So to say that nothing can survive in a 0 oxygen environment would be a false statement. There is always the risk in deeper pockets of creating hydrgen sulphide gasses but these instances are rare unless you are creating a bed of 6" or more.

Here is another short but in depth explanation of the reactions creating the cycle. In the process of nitrification of wastewater, the two key bacteria of ecological importance are nitrosomonas and nitrobacteria. These bacteria facilitate "catalyze" the reactions. Nitrosomonas results in the removal of three pairs of electrons from ammonia facilitating the formation of nitrite and nitrobacteria removes two electrons from nitrite to form nitrate. The bacteria responsible for denitrification are autotrophic and heterotrophic facultative anaerobes.

 

[Gealcath]

Anerobic is low Oxygen (There is hardly any Oxygenated water but there is Oxygen present), Anoxic is 0 Oxygen (no Oxygen whatsoever), which is what i am comparing, there 2 diffrent areas, the 2 often get confused.

 

[kraig m.]

thanks everyone for all the help. I'm on my way to getting rid of the nitrates. If there is anything else that needs to be added, I'm up for all that has to be said. But I beleive you all have pretty much covered everything that I need to know. And thanks again.
kraig m.