Re: NANFA-L-- Bubbles from the substrate

Subject: Re: NANFA-L-- Bubbles from the substrate
From: Todd D. Crail (tcrail-in-UTNet.UToledo.Edu)
Date: Sun Dec 26 2004 - 22:14:08 CST

----- Original Message -----
From: "Sajjad Lateef" <>
My guess is that there is anaerobic decomposition going on
in the substrate and the H2S is building up and slowly

Hi Sajjad,

It could be a lot of gasses. It could be CO2 released from the respiration
of the biofilms processing the mulm (the films trap the CO2 until it can
overcome the surface tension). It could be methane released by autotrophs
in the same films. Or yeah, it could be sulfides.

In my book, if you can't smell it, it's not a problem, and even then... Not
really, always. Sulfides happen. I have had large fish die for whatever
reason, be caught up the jungle of my tank where I can't see them rotting
away below the surface, nasty crusty film going across the top of the water,
and actually SMELL their presence first... With no one one else any worse
for the wear. I'm talking like putrified, sliming through my hands when I
pick it up, "Oh that's gonna be tough to get rid of", the dogs rejoice-in-
the opportunity to even think about rolling in it, rotten. Gross huh?

Nitrates also happen, but those don't stink, and so sulfides make a much
easier "culprit" to blame when things go poorly. It's easier to lift an
undergravel plate, see a bunch of bubbles come up from the 1" layer of
compacted mulm and say "Well this must have been sulfides that killed my
fish!" than admit it was really just a lack of design that wasn't processing
the _nitrogen_ OUT as a, well, more respectable bubble of gas (N2), or just
a lack of the more conventional method and age old standard... the water

So... I'd be looking-in-nitrates, and if they're in check... I'd call it a
day and spend my time in wonder about all the little critters in there doing
their business. :)

The Muddy Maumee Madness, Toledo, OH
It's never too late to have a happy childhood.

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: Sat Jan 01 2005 - 12:42:05 CST