Re: [Killietalk] azolla (was duckweed)

["Dennis Heltzel" <killies at fishroom_net>]

> I'm wondering having those plants that grow on the surface of the water,
> how would it affect the gas exchange? I would normally prefer those plants
> that is submerged in the water.

Generally, floating plants will increase the amount of gaseous exchange
compared to submerged plants. They are photosynthetic and so produce lots
of O2 while consuming CO2. If the water or air is turbulent, then this
probably dissipates rapidly, but then there will be plenty of gaseous
exchange going on anyway.

If the floating plants get very dense, some air breathers might have a
tougher time fighting through it. I see this in a 55 that is choked with
Riccia. The cories have to work a bit to find a way to the surface, but
they manage.

-- 
Dennis Heltzel
Keystone Killy Group
SE Pennsylvania, USA
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