Nitrogen Cycling Revisited: Sand, critters, carbon, and why you may be under-feeding

jda123

Dolphin
M.A.S.C Club Member
#21
If you slowly work to double the feedings, then the microfauna and bacteria in the sand and rock will have time to build up and they can handle the double food. If you double too quick, then you will have to wait until you stop incrementing to see the N and P go back down. The tank is not carbon limited in this case, it is time limited. The microfauna and bacteria in the tank can double as well, they just need time. My tank could handle this, but I would need to flush my toilet more often. Every tank has a point to where you cannot double anymore - even tanks with organic carbon dosing or tons of GFO - but I don't think that anybody is advocating taking a tank to the breaking point using any method.

The bacterial beds that you see are a net-neutral to the tank. They are just temporary storing the N and P. Unless you export the bacteria, they will give the N and P back if you stop dosing the carbon and they die.

The food is full of carbon too and was mostly balanced when whatever was in the food was alive - there is likely enough carbon there in most foods to grow the necessary fauna to process it, if they are the right kind of fauna. When you grow the bacteria in the water column and on the surface, you use the N and P that the microfauna and bacteria deeper inside of the rock would have used to grow to equilibrium with what you typically add daily for food. Growing it on the surface is fine and all, but you shifted the onus onto the reefer to supply extra carbon to process the same things (N and P) that could have been taken care of by other organisms without the extra vinegar.

I don't know of any filter feeder than can feed on food as small as bacteria. They are not even a micron. Pods cannot. Neither can even fine filter feeders like Tridacna. I know that I have seen articles that say that the bacteria can feed tank inhabitants, but then you see others that unequivocally say no... so I don't know what to believe. In any case, most will agree that the feedings are not necessary and the coral and stuff can live without them if they do even eat them.

It just hit me why you might be happier with your DC Octopus skimmer than I was. I don't have the extra bacteria to skim, so my output is lower. Here is a photo of my ASM G4 after 24, and then 48 hours when I dosed sugar. I had to clean this disgusting mess every 2 days. Amazing results, IMO:

 
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