Hi all,
I just don't get why bottled ammonia is being viewed as more poisonous than the inorganic result of organic decay and metabolism.
It isn't any real difference, in solution they are both NH3/NH4+ (dependent upon pH). The main difference is between the small amounts that are continually diffusing from the bioload (shrimp/fish/snails etc), and adding ~ 5 ppm in one hit.
The problem really comes with the whole concept of "cycling", it is based upon the idea that all the nitrifying bacteria are in the filter media in the filter and that if they don't get a constant supply of ammonia they will all die, this is an extremely dubious premise at best, and as soon as you add plants and substrate it is virtually irrelevant. You also have to factor in that "plant/microbe systems" are about an order of magnitude more efficient than "microbe alone" systems in processing ammonia.
In reality if we have plants we just need to ensure that we have high levels of dissolved oxygen and some supply of carbon (usually as HCO3-). Plants (and particularly those with emergent stems or floating leaves) are a "
win,win, win" scenario, they add dissolved oxygen (even outside of the photo-period, and into the substrate via the root rhizosphere), they preferentially take up ammonia (and NO2/NO3), and they provide surfaces for nitrification.
Environmental scientists, the waste water and aquaculture industries etc. don't talk about cycling at all, they are interested in "Biochemical Oxygen Demand" (BOD) <
Biochemical oxygen demand - Wikipedia, the free encyclopedia> & <
Carbonaceous biochemical oxygen demand - Wikipedia, the free encyclopedia>. As a
"rule of thumb" in any system as long as the oxygen supply exceeds the oxygen demand then the system won't crash.
I wrote this for the keepers of fish with high oxygen demand a few year ago, but it is relevant to all fish keeping <
plecoplanet: Aeration and dissolved oxygen in the aquarium>.
cheers Darrel