Want a maintenance-free substrate- SSB or DSB for 30"x18"

[Newreeflady]

lmao!!! I'm really sorry to hear that. I know how it is, I've gone through a lot of system issues as well. One of the main reasons I'm willing to reexperiment with a dsb is that this system will be torn down in 3 years- I might be more hesitant if not. I'm hoping that somehow, someway I can make this work. I know some have had good experiences, but that many have not. I'd like to be on the side of some, and I think that will take a good deal more planning and reading a bit of diligence to maintain the life in the bed. We shall see.

Anyhow, you guys have both helped a lot- thanks! As I think of more questions I'll post them up. If you remember something and it seems important to tell me, please do, either here or by pm if talking about dsb is uncomfortable in this webspace.

Cheers,
Angela

 

[tmz]

Hey there,

Just to keep it on a technical level, I should mention that I am an organic chemist

That said, my bio knowledge is generally poor:/ So, let me see if I have it right in my mind at this point. With a DSB I will have much more bacteria than the average joe reefer. When I feed in vinegar, I am feeding in a source of food for them. In using this food, they also consume oxygen and thus lower the oxygen level in my aquarium- this is the concern, yes?

The article I've been going with for the kalk thing says:

Dissolving the Kalk powder in the Vinegar first will accomplish several very good things.

...after all the cool Calcium ion chemistry is over, the leftover Acetate ions from the broken-down Vinegar leaves you with free organic Carbon in the water that feeds the bacteria in your tank so that it converts more poisonous Nitrates to NO2 gas (a very good thing).

So, your concern is that the bacteria will run out of NO2 to process, move on to PO4, then to H2S?

-A

Easy on the technical, I suspect your knowlege of chemistry is beyond mine.

With a well functioning sand bed you will have more surface area and potential anoxic areas for heterotrophic bacteria to denitrify. Wether or not you have more bacteria or not depends on how much "food"( organic carbon, nitrogen and phosphorous) is available . All three of these are consumed at the same time and are used to form proteins tissue ,dna etc.All three are needed in addition to oxygen(O2-->NO3-->SO4) for energy via respiration.

Yes, O2 depletion from bacterial blooms is a potential downside of organic carbon dosing when overdosed.
BTW carbon dosing encourages aerobic bacterial activity in the water column where the nitrate is assimilated for the nitrogen as well as anaerobic activity on surfaces in hypoxic areas where it is stripped of oxygen leaving N2( nitrogen gas) When overdosed cloudy water and usually results from the aerobic bacteria.
Most strategies employ a very low dose starting point ramped up over months. Personally I have been maintaing a dialy dose of 60ml vinegar and 26 ml vodka for a 550gallon well fed system with many corals and over 40 well fed fish for the past 14 mos with no ill effects and very low nitrate(<.0.2ppm) and PO4(0.04ppm).

With excess organic carbon, the bacteria can deplete the O2 in a given zone or the whole tank for that matter. The oxic areas become hypoxic(low in O2) and some bacteria then use NO3 for the oxygen leaving harmless N2 nitrogen gas as byproduct. Existing hypoxic areas such as in deep sand beds which already recieve limited oxygen and some nitrate can become anoxic when organic carbon is added as the NO3 may be used up by accelerated bacterial growth and then they go to SO4 for oxygen with HS2 as a byproduct. Hope that helps

Organic carbon may olso build up without attention to export via heavy skimming and gac, purigen etc.

It's as many things are in this hobby a matter of balance . Since deep sand beds likely have more hypoxic areas by design the chances for anoxic areas to form is greater.

 

[tmz]

Edit: First sentence should read:With a well functioning sand bed you will have more surface area and hypoxic areas for bacteria to perform dentirification. Not more anoxic areas although the potential for anoxia is greater.

Just to iterate. The bacteria don't move on to PO4 they consume it right away along with N and C for the P not the O directly. The progression for respiratory O2 is O2, NO3 and then SO4. Think of it as two processes :feeding on C, N and P and respiring O2 and whrn it's gone taking it form NO3 and when that's gone taking it from SO4.

 

[Gravesj1s]

~Angela,

Wondering if you had any updates on your DSB.Have you started to set it up?