SPSHolic's Blog

No ... a brown film is either diatoms, or dinoflagellates. These will result from an excess of either a silicon, or phosphorous, respectively.
Neither the green or brown films are fueled directly by a carbon source overdose, however ... a carbon source overdose can unbalance the relationship between nitrogen and phosphorus (N:P). If the N:P ratio that emerges after a carbon source overdose has a high concentration of N, then green algae (and microalgae as well) have the nutrient they need for exponential growth. If the N:P ratio that emerges after a carbon source overdose has a high concentration of P, then dinoflagellates have the nutrient they need for exponential growth. If there is also Si available, then diatoms can demonstrate exponential growth (... but this is probably a RODI filtration issue at its core).

If you're going to use color as the diagnostic, then:

Green --> algae
Brown (filamentous) --> algae
White --> bacteria
Red --> cyanobacteria
Brown (non-filamentous) --> dinoflagellates
Brown (slime) --> dinoflagellates
Golden Brown --> diatoms

Yes ... in fact, the whole biochemical point of carbon dosing (not just overdosing) is to alter the N:P ratio of the system. For non-photosynthetic bacteria (and several other groups of non-photosynthetic microorganisms in our tanks), carbon is a "limiting" nutrient for growth. When we provide a labile (useable) form of organic carbon, growth and metabolic behavior that would otherwise not happen ... begins to happen. Such growth and metabolic behavior consumes and/or catabolizes N and P. As a result, the system's N:P ratio changes. Different microorganisms have different optimal N:P ratios. As the system's N:P ratio shifts into a particular microorganism's optimal N:P ratio range, that microorganism begins to demonstrate exponential growth.

----------------------------------------------------------------
N:P ratio is nothing more than the amount of nitrogen to the amount of phosphorous. In our marine aquaria, it is roughly the ratio of [NH3] + [NH4] + [NO2] + [NO3] ... to ... [PO4] + [unmeasurable P compounds]. It's important because different ratios are preferred by different microorganisms, i.e., at different ratios different microorganisms will grow exponentially.

Anything that is growing on your glass that is 'green' is not a result of a carbon source overdose. 'Green' is the indicator that the microorganism in question is probably photosynthetic. Photosynthetic microorganisms (like green & brown, diatoms, and dinoflagellates) are able to extract the carbon that they need from inorganic sources like CO2 ... they are never carbon limited, so their growth is only weakly associated with carbon dosing, if at all.

Non-photosynthetic ('heterotrophic') bacteria, when their colonies grow large enough to be seen by the human eye, will generally appear to be white or grey.

Noticed in Algae/Bacteria Reaction
1) Bacterial Blooms (slimy white strings) = too much bacteria, decrease vodka dosing.
2) algae on glass after increase of MB7 = reduce MB7 :P
3) brown dusting or brown hair like stuff = decrease MB7 (also check http://www.rimlessreef.com/1/post/20...eament-of.html )
4) cyano = increase MB7 and/or lower/stop vodka dose. After the cyano has gone away restart the vodka from the initial or maintenence dose. If it's really bad consider a "lights out" period. If really really bad consider "Red Slime Remover."
5) peach fuzz = stop or decrease (especially vodka) dosing for a while (about a week or till the fuzz dies off) then start back up with the maintenance dose. OR This may also just go away in time.
6) glass and sand getting dirtier = dose more/feed less