"dc" wrote in message
...
Köi-Lö $##$$@$##$$.#$$ wrote in
:

Some people claim toxic gasses accumulate in the gravel, especially if
no live plant roots are running through it. I do have live plants in

The toxic gasses arise from some types of anaerobic bacteria. It is not
especially common, but it is a potential problem if you have a very dirty
or very deep gravel bed. Using gravel heating cables will generate a
natural rising water flow and prevent the development of these gasses.


To my knowledge I haven't had any of these toxic gas problems. I don't have
very deep gravel in my tanks and do vac it regularly. All the gravel in my
tanks are full of plant roots which may also be helping. I read about
heating cables but they're too darned expensive.
--
KL....
Frugal ponding since 1995.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
http://www.ganesha.org/ptb/hipcrime.html
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