[APD] RE: Fertilizing a new tank(when to start)

["Jim Seidman" <james at mail1_seidman.net>]

Scott H. writes:
"Okay. That makes sense tome since substantial build up of
food for the anaerobic bacteria will take a while to occur
as will the population of bacteria. Then that suggests that
fresh substrate doesn't pose problems N problems and isn't
a reason to avoid feeding plants, even in a new tank."

How long is that? I honestly don't know how fast denitrifying bacteria grow.
But if you're fertilizing the plants, then the bacteria must have all the
nutrients they need to grow too.

Scott H. writes:
"If there was a large mass of such bacteria, shouldn't they
then be turning nirates back to nitrites? Isn't that one of
the features of anaerobiec bacteria?"

There's a whole denitrification cycle:
NO3- -> NO2- -> NH4+ -> N2

Just as with nitrification, different bacteria handle different stages, and
you can have incomplete processing where the cycle doesn't finish. In my
tank, I never saw very high nitrite levels, although there may have been a
spike that I missed. But given the NH4 spike, much of the nitrite must have
been converted to ammonium.

Robert Ricketts writes:
"When ammonia or nitrite
are produced in the substrate, there should be enough oxidizers (facultative
or aerobic) at higher levels of the substrate to oxidize any leakage before
it hits the water column."

Literature on unplanted tanks says that establishing the nitrifying bacteria
is a process that takes weeks. Why would a brand new planted tank have
enough oxidizers? And why would they necessarily grow faster? Remember that
at first you're starving bacteria that consume NH4, but heavily feeding
bacteria that consume NO3 (if you're fertilizing a brand new tank, that is).
So is it possible that denitrifying bacteria that consume NO3 could get a
head start on nitrifying bacteria that consume NH4?

Robert, in your tanks what kind of NO3 concentration were you maintaining?
When I bumped my NO3 level from 1 ppm to 10 ppm, it produced a measurable
NH4 spike that lasted for days.

- Jim Seidman


_______________________________________________
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com
http://www.actwin.com/mailman/listinfo.cgi/aquatic-plants