O.C.'s Pellet questions and answers!

[OceanicCorals-Ian-]

Originally Posted by Delphinus

FWIW, I have run with the pellets both with UV and without. In fact, I am currently running 57w of UV because due to sloppy QT practices on my part I introduced ich to my established livestock (luckily, the UV seems to be helping). At any rate, the nitrate reduction capacity of the pellets does not appear to be diminished.

Having said that, I would prefer not to run UV at all and plan to disconnect it at some point. It is simply a bandaid in the meantime.

Regarding monocultures .. I believe this is a key issue with a few tanks that are not showing dramatic nitrate reduction in the timeframes that others have seen. Plus, nitrate can be bound to substrate (rock and sand), once this happens, it can take a much longer time to see a reduction in the water column readings because as soon as it is removed from the water (ie, by bacterial uptake), it is replaced out of that bound in the substrate. This is not too uncommon, and the solution really is just patience for the most part.

However a bacterial supplement idea has merit. When I started pellets I ran both zeovit and pellets and saw a tremendous reduction of nitrate in a very short order of time. However, I realize now this was due in part to the systems running in parallel and that zeovit requires you to actively dose bacterial strains. When I ran the two systems together, I could test nitrate at the input and at the output of the pellet reactor and could see a noticeable difference (in fact, I would get zero readings in the effluent). Since disbanding zeovit and just staying with pellets, the difference now is more subtle. This makes sense to me: the daily added bacteria was consuming nitrate in a frenzy, but was not a sustainable culture. Thus when stopping the dosing, my tank in fact showed an increase in nitrates and took close to a month or maybe even a little over a month to start showing a decrease once again. Only now about two months after do I get close to zero readings again.

Thus I offer the 2 lessons learned:
1) If you want a faster reduction, you can consider a bacterial supplement such as Zeobak or LB7 or similar product. But ...
2) The flipside is that unless you are comfortable redosing these on a permanent basis, when you STOP dosing it, the bacterial cultures will have to adjust themselves to a more self-sustaining population and this will take more time.
3) The pellets DO work on their own, they are far less troublesome and maintenance intensive than other systems .. the worst case scenario is you may simply need to wait for it to establish. Thus (like with many things) patience is a virtue and all that good stuff.

HTH..

Very well written and looks to be bang on, good call Tony.

Ian
O.C.

[DiverDude]

ok, noob question here....the term "monoculture" has been used a bunch of times in this thread and each time I hear myself saying "and just what the hell is monoculture?"

Clearly it is a singular strain of bacteria of some sort but which one and why is it so relevant to NP Pellets ?

Enquiring minds what to know !

[Zoaelite]

Having a large varied biomass of bacteria maximizes the types and amounts of nutrients exported out of your system. A single type of bacteria is suited for what it requires while many different species cover the whole spectrum.

That being said, very little is known on the relationship between Bacteria and their surroundings, this is something that is currently being studied. Most of the bacteria supplements we add to our tank are nitrobacter or Nitrosomonas but here is a statement from Ency. Britannica to give you a little info.

any of a small group of aerobic bacteria (family Nitrobacteraceae) that use inorganic chemicals as an energy source. They are microorganisms that are important in the nitrogen cycle as converters of soil ammonia to nitrates, compounds usable by plants. The nitrification process requires the mediation of two distinct groups: bacteria that convert ammonia to nitrites (Nitrosomonas, Nitrosospira, Nitrosococcus, and Nitrosolobus) and bacteria that convert nitrites (toxic to plants) to nitrates (Nitrobacter, Nitrospina, and Nitrococcus).

[Werbo]

N/P pellets are part of the evolution of carbon dosing and the first "solid" vodka method. Carbon dosing in some form is key to Zeovit and other UNLS systems. Vodka was a cheaper alternative. Early criticisms of dosing vodka alone was that it would produce a monoculture of bacteria in your aquarium and limit the diversity of good bacteria. Vodka is not the only carbon source. A variation that incorporate vodka-sugar-vinegar and incoorporated biodigest became quite popular as theory of the VSV method was to avoid a monoculture. Here is a good read.

http://glassbox-design.com/2008/achi...perimentation/

As far as I know the make-up of N/P pellets is still unknown so some critics fear it will create a monoculture of bacteria, especially after longterm use.

[DiverDude]

So in a nutshell, a little bit of a lot of different types of bacteria is what we want. A lot of a single strain is not (probably runs amok !).

I hope to have pellets online tonight so we'll see how it goes.

[Werbo]

If it was me I'd start dosing a bacteria source first for 2-4 weeks before starting the pellets in a fluidized reactor. I use Brightwells Microbacter 7 (its cheapest) but Prodibio biodigest or whatever Zeo calls their bacteria culture. Build a diverse bacteria population first and then begin exporting it via carbon dosing/protein skimming.

[DiverDude]

Interesting thought. I was planning on running about 1/10 of a bag (so ~100ml) of pellets to start. After a few weeks, I was going to double it and run with a total of 200-250 ml.

The thought was to not shock the system too much. On top of that, I've just torn the tank apart to add the sump and re-aquascape so it's almost 100% new water and freshly cleaned sand so I'm a little low on bacteria right now.

Maybe I need to rethink this.