Re: Under Gravel Heat (Digest #91)

Dave Gomberg wrote: 
>Aquatic Plants Digest        Sunday, 28 May 1995        Volume 01 : 
Number 091
>Subject: Re: Aquatic Plants Digest V1 #90
>A thought I have had on undergravel heaters:
>Most all aquarium stands are in some sense hollow, either a "hollow"
>cabinet or "hollow" cement blocks or....   What if you heat your tank
>by putting a heating facility BELOW it instead of IN it.  The
>thermostat still goes in the water, but the heat itself comes from
>below.  Now the gravel has the best of it (heatwise) and the plants
>should do very well????   Dave

Broad-area heating under the tank is radically different from the 
narrow strip-heating effect advocated by Geo. Booth and others. The 
wires create small, gentle convection currents, causing nutrients to be 
sucked down in the spaces between the wires to displace the rising 
water over the wires. The water moves more gently than with a UGF, but 
it does move.

The situation you describe has the potential for going totally 
anaerobic and creating a very smelly mess. Something to cause some 
slight circulation of water in the substrate is needed. [IMHO :-)]

What do I know, tho, for I am still a fan of UGFs, properly used. I 
never needed the stability of substrate heating, for I can't leave a 
tank unmolested long enough for it to have any advantage. My plants so 
overgrow my tanks that I have to strip them out and redo every few 
months, anyway. Maybe, someday, I'll learn to plant more conservatively 
and for more permanence where substrate heating becomes meaningful.