Re: [APD] Cycling

["Robert T. Ricketts" <rtricketts at verizon_net>]

Folks talk about fishless as a generic cycling technique.  But there are
many versions of it in the web, and many to most are flawed.

It seems that the original technique, set by Dr., Chris Cow, a.k.a. Nomad,
has been forgotten and the original site is long defunct, Tom's Place
Aquarium Boards, in AquaSource Magazine.

That technique called for an inoculation with nitrification bacteria by
using the rock wool from potted aquarium plants (best if freshly received at
the LFS). The bacteria present are spurred into growth by an initial ammonia
titer of 3ppm.  As soon  as nitrite appears at any detectable level, the
ammonia is cut in half, and maintained at 1 - 1.5ppm maximum for the rest of
the run.  My first trial as a beta tester of the technique was slow, 4
weeks.  But Chris straighten me out - I had just used some of my own plants
from another tank - I missed the point - the plant does not matter at all,
what matters is the rock wool which tends to develop a nice nitrification
colonies while the plants are developing as immerse plants over submerse
pots in circulating hydroponic solutions.  The rest of my trials in the
series ranges from under two weeks to a max of 2 1/2 weeks.

After the beta testers spread the word around the web, the technique caught
on - as we hoped and wanted. One glitch showed up and was corrected.*   Then
variants started appearing, and over time many showed marked increases in
the ammonia titer used - no doubt on the theory that if a bit is good, more
is better. I think and hope that most us know better than that.  Years later
I ran a trial (with field grade test kits a log more sensitive) and cycled a
filter without ever having detectable ammonia. keeping it below the hobby
kit detection levels.  It still worked.  High titers of neither ammonia nor
nitrite are required and certainly may be inhibitory.  I never tested high
nitrate as inhibitory, but it would not shock me to find it to be so.  When
you see folks using too much ammonia, or with excessive nitrite or nitrate
titers, suggest that they partial to get any or all of those down, and to
keep the ammonia low.  The original technique worked then and still does.
The variants may or may not.  But if they never inoculated the tank at all,
they are swimming against the tide.  Without starter bacteria, the time is
open-ended.

*The glitch was that none of the beta-test folk had soft water.  We totally
missed the fact that there would be buffer issues with extended cycles
without partials or KH supplements (each milliequivalent of ammonia oxidized
to nitrate requires two milliequivalents of bicarbonate - e.g., KH).  Loss
of buffer can pH crash the tank, and the nitrification bacteria are best at
alkaline pH anyway, slow down growth below pH 6.5 and may stop below pH 6.
So, we then suggested that everyone monitor KH during the development cycle,
and partial as required to keep KH above 2 degrees (~36ppm).  Higher would
be safer and likely a bit faster, but if they have at least that much
natural buffer, they will cycle okay.

HTH

RTR.




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