Quote:
Originally Posted by Dan_P
Yes this is good read if you want to know about the science behind carbon dosing but a somewhat more readable version was presented at the 6th International Conference on Recirculating Aquaculture. It is published here.
https://ejournals.lib.vt.edu/ijra/ar...view/1336/1814
Figure 2 is important to put the ideas in this post in perspective. The bar chart reflects Jonathan’s perspective. Unless the C:N ratio is very high, you always have some autotrophic activity. Ending carbon dosing suddenly when the system is heavily dependent on heterotrophic activity to remove nitrogen seems likely to produce an ammonia spike, but you haven’t provided evidence or calculated a C:N ratio for a typical aquarium to show whether the typical aquarium heterotrophic:autotrophic ratio is on the edge of disaster. The notion to use care tapering off carbon dosing is sound advice. Whether a sudden cessation is dangerous has yet to be demonstrated.
Where I think we missed an important point in this discussion is that the ratio of heterotrophic:autotrophic may be predictive of a system’s propensity to grow nuisance photoautotrophs such as diatoms, dinoflagellates, cyanobacteria and algae. The notion that nitrate and phosphate are predictive or are the cause of nuisance organism growth needs to be revisited. It might be more useful to think in terms of inadequate heterotrophic activity or a low C:N ratio as the cause of nuisance organism growth. |
Both publications are available and included in my article including a lot of other publications
http://www.baharini.eu/baharini/doku...onium_reductie
It is known that autotrophs do not care at all about the presence of heterotophs and that it is just a question of available organic carbon and competition for the same building materials. And there will be always autotrophs present in an aquarium, they will not be wiped out.
The problem is the difference in growth rate. They may be suppressed and drastic be reduced in a few hours to days, but they need time to reinstall when given the space. Autotrophic decay feeds heterotrops due increased availability of organics.
This threat is not about the influence of nitrate on the system but about how to have control over the nitrate production and removal in function of maintaining the carrying capacity needed. Most organism prefer ammonia above nitrite and nitrate as nitrogen source for celsynthesis. , Respiration is also a factor of big influence.
How to control nitrate and what is the safest way to do so.?
The fact that carbohydrate dosing will reduce the nitrification capacity is not a problem as long the carrying capacity is not changed. The problem is that when the dosing is interrupted the carrying capacity will change. When the change is to big it will have its effect and its consequences. Dangerous? A system that may loses a part of its carrying capacity from one day to an other, yes I find this situation dangerous. It is a risk one does not have to take, not for fine tuning the nitrate level.
When one messes with nature it has always consequences. It is important to know what may happen before starting messing with it.