Backyard Aquaponics
A place to discuss aquaponics

OK sorry the green line.

Rupe's assertion is that the green line will not start going up until 25 days when the red line is zero, instead of 10 days as on this graph. Nitrobacter takes longer to establish, which I thought was the reason why the nitrite is not dealt with as fast as the ammonia.

I'd like to see the info that says nitrite->nitrate is suppressed by non-zero ammonia levels.

If this graph is typical it looks like the red line can be ignored as a factor in the nitrite->nitrate conversion, as the relationship between the orange and green seem like they are behaving as if the red line is not having an effect on them - the green looks like the orange line but with a slight lag for the bacteria to establish.

Might be amoungst this mumbo jumbo http://aem.asm.org/content/64/1/258.full

Try a google search... "ammonia inhibits nitrification" ... there's many papers written... but Hovanec et al probably have the most "recent" and best...

The best links I found.. were included in my article in the BYAP Magazine Vol 5....

That is a revealing article. I can't understand why we are still talking about ammonia and nitrite conversion in terms of Nitrosomonas and Nitrobacter species. This research clearly shows that it is Nitrospira species rather than Nitrobacter species that are responsible for the conversion of nitrites into nitrates.
I assumed that this was new research but was shocked to find that it is now 15 years since this article was first published. Has the research since been discredited? If not then I suggest that we refrain from any further reference to Nitrobacter bacteria in relation to freshwater nitrite conversion.

No.. the research has not been discredited... but in fact confirmed....

And yes.. we should be referring to Nitrospira... not Nitrobacter... and these days in scientific circles that's pretty much the case.... (although there's still some hang over in waste water treatment circles... for specific reasons)...

But changing a long held paradigm.. especially amongst the aquaria community... will take time....

Major ugly truth of AP in a prepping situation is getting baby fish, food and parts/maintenance and regular power supply in a SHTF situation.

Thanks Rupe I did try Googling and didn't see anything.

Nitrospira needs a better marketing department:
http://www.google.com/trends/explore#q= ... nitrospira

There is definitely a lot of mythology in the aquarium trade, prophylactic salt (NaCl) use is one of them. It's not all witchcraft and wizardry, though, thanks in part to people like Dr Hovanec. He's one of the people that have started moving the industry away from those sludge remover/waste treatment nitrobacter heterotrophic bacteria booster products and into the proper chemlithotrophs responsible for nitrification in aquaria naturally.

Regarding the statement
To clarify, the concept is based on regular testing and redosing ammonia to maintain a 4 to 5ppm level. Whether you consider it impossible or illogical is irrelevant to the fact that many people use this method. Personally I'm not a big fan of fishless cycling, I do my tanks with fish-in, but I know many people who do prefer fishless and this is what they do, and it works for them.

I think the main point is that it's a continual process, with both species of nitrifiers doing their job in tandem. There is an initial spike in both the ammonia and nitrite readings as it takes time for their respective nitrifiers to colonize and begin to make an impact.

Since we have brought up Dr. Hovanec, here's his guide to fishless cycling. This, to me, runs counter to the statement that "The nitrite to nitrate conversion... is inhibited by ammonia... and wont begin until ammonia is effectively zero...."
http://www.drtimsaquatics.com/resources ... ss-cycling

specifically "When ammonia and nitrite are both less than 0.5ppm (NH3-N or NO2-N) add more ammonia to 3ppm." and "Now measure every day, when ammonia and nitrite are both 0ppm, add more ammonia."

I'm more heavily into the aquarium side of aquaponics, and there is a lot of wives tales that run about, but there are also a lot of people who have made great strides iin trying to better understand the processes that we encounter in aquaria.


From how I understand it, plants can use both. Some species prefer one over the other (duckweed for example). There's plenty of dry reading on the subject via a google search.

One example from this link.
http://filebox.vt.edu/users/chagedor/bi ... trate.html



I'm not trying to be controversial, just trying to flesh things out.

Your plants won't grow much when it gets cold. Whether it is from the nutrients or what, I don't know, but us northern gardeners don't plan for growth in the winter. You plant what you want to harvest in late July or early August and put a cold frame over it when the frost hits. And it just sits there in a sort of suspended animation until you've either eaten it all or warmer temperatures come.

Dana - I have personally harvested many leafy greens during this winter with very few fish in my system. One does not necessarily have to consider Ap a summer only activity if you plant specific plants imho

I'm hoping for that, tojo! Lettuce doesn't seem to be doing very well for me, though. Beans, peppers and herbs (except basil) are all happy and the lettuce for the most part gets an inch tall and then whithers and dies. I have some that finally made it past that, though, so here's hoping!

(I think it is because my pH was 8.4 and I have hard water. The biological filter seems to be kicking in and the pH dropped to 7.8, which still isn't quite where I'd like it, but that's when the lettuce started to look like it might actually produce something for me. And that reminds me . . . rain is on the way and I haven't put out my buckets to collect what I can!)