Re: Under-tank heating coils.

On Thursday, 1 June 1995, Charles Bay wrote:

> One issue was that heat coils IN the substrate would provide better
> granularity for convection currents for better over-all circulation.
> OK, I buy that.

I have a bit of trouble with this assumption.  If I were to uniformly heat a
container of water from below, I would expect to see the formation of
roughly hexagonal convection cells, each with warm water rising in a
narrow column at the center and cool water subsiding around it.  Buried
wires presumably give rise to linear cells.  For a given amount of heat
applied to the system I would expect the same rate of water transport
through the substrate.  Why would either system have any advantage over the
other?  How can a plant distinguish between linear and hexagonal convection
Kevin Conlin   kcconlin at cae_ca   "We're Canadians.  We HAVE to be polite"