Re: under gravel heating cables

["Ed" <ed at pattravers_com>]

Don scribed the following:

""I quote Dupla, We know from detailed observations in nature, that water is
constantly flowing through the plants root areas. This is due to groundwater
currents. This movement of water may be horizontal, but can also occur in a
vertical movement due to changes in ground water level. This phenomenon has
a great advantage: the water flow constantly supplies oxygen to the soil and
 thus prevents any decaying and blackening of the substrate. Nutrients are
also continuously supplied to the plants roots. With a substrate heating
system we achieve a water circulation which comes close to that in nature,
thereby obtaining a healthy and breathing substrate.""

<rant on>
This sounds all to simplified to me.  I find it hard to believe that
wherever plants grow in nature there are groundwater currents flowing.  I
don't think that is even close to being factually correct.  I'm surprised
that Dupla would make such a statement.  It sounds to me like a sales pitch
for their substrate heating cables.

Why and where aquatic plants grow in nature is as varied as the plants
themselves. 

Certainly groundwater currents can be present and even beneficial to some
plants and environments but it is not the blanket case.

With that said - I am not saying that substrate heating cables are not
beneficial to the home aquarium but I do take exception to the Dupla claim. 


Substrate heating seems to be one of those areas that some people swear by
and others never even consider.  Personally I have never seen a need for
them. 

As far as substrate circulation goes, I believe that (in nature) it is far
more feasible that the plants themselves transport water, as they do
nutrients, from the substrate up through their stems and leaves.

While that might not be as efficient as Daupla cables it has been working
just fine for millions of years.  

One last thought... I have been keeping planted aquaria for several decades
and have never experienced "black" substrate.  If I ever did I think I would
get out my gravel vac.
</rant off>

Regards,

Ed

http://www.pattravers.com

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