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Re: [APD] Re: Minimum Light Threshold

--- Bill D <billinet at comcast_net> wrote:

> Variations in lux from bulb to bulb would show the
> differences 
> in the amount of light energy that is reaching the
> plants, 

But perhaps not how much useful energy is reaching the
plants ;-) It's quite possible that one bulb with a higher
lux actually provides less useful light as far as plants
are concerned. So I don't see how it's an improved tool. A
possible example based on Ivo's results is the comparison
of the Powerglo and Sunglow bulbs -- under otherwise
identical set-ups, the Sunglo case will present higher lux
but the Powerglo higher useful light to plants, unless I am
missunderstanding Ivo's results. Of course, as I've said,
using diff ballasts, and other factors, might change 
the results. Yet, either bulb will work pretty well based
the watts involved. One a bit more than the other?
Probably. enough to make or break a tank? Undoubted not.

> and 
> it is that energy that is important, not how much energy
> the bulb 
> requires to light up.
> As Scott said, PAR would be a better measure.  Or, as Tom
> said,
> "micro moles of photon's (or Einsteins/units of quanta) "
> would be
> best.
> When I first started in this hobby incandescent lights
> were the standard
> and people still talked about "watts per gallon."  Years
> later we are 
> still using it, and defending it.  It is long past  time
> for an upgrade.

I have a similiar problem with some software -- a Newgrade
isn't necessarily an upgrade. So I would agree but only if
an "upgrade" actually proves more useful, which remains to
be seen, imo.

Scott H. 

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