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Re: Review: Wonder Lights

On Mon, 31 May 1999, Moishe Wasserman wrote:

> A month ago I bought Wonder Lites.  Wonder Lites are mercury vapor bulbs
> thats screw into a regular socket.  (More info at thekrib).
> My tank:
> 35 gallon

> Previous to my use of the new wonder lights I had three 90 watt halogen
> floodlamps and tw0 30 watt blue and red fluorescents. 

Let's use the liberal estimate that halogen's are 1/3 as efficient as
fluorescent or gas discharge lighting.  That's (90*3)/3 + 60 = 150 watts.  
Pretty much right on the high end of the 2-4 watts/gallon guideline.

> In the weeks
> following the placement of these three 160W lamps, the plants seem to die
> out.  New growth was rare and stunted and the water turned cloudy..  The
> wisterialiterally crumbled, the bacopa turned black and stopped growing, the
> ludwigia turned very blackish and died, and the cardamine died.  The
> ech.cordifoulous just turned brown.

Holy crap! 160x3 = 480 watts over a 35 gallon tank?  No wonder they died.
Way too much.

> Ahem, I dished out a respectable amount for these mercury lamps, can someone
> please explain to me what I did wrong?  Or does this prove that halogen is
> better than fluorescent?  In all my attempts to grow plants, I have always
> succeeded with halogen, yet have had limited results with fluorescent.

Well, first of all, Mercury vapor is not fluorescent.  Second, the reason
many of us tend not to recommend halogen or other incandescent lighting is
not because your plants won't grow, but rather because you have to use 3-4
times as much power to get the equivalent light (and risk baking your
tank, not having a 5000K color balance, etc).  In fact, some have
suggested on this list people might have good luck using incandescent
bulbs to flower Echinodorus species (because of the infrared emissions?
check the archives).

Whenever you change the lighting level drastically on a tank, things are
going to get thrown out of balance, and there's a recoil time.  However,
tripling the light over a system already near maximum is just not good.
Perhaps there's something you're not telling us about how the lights are
set up ("Oh yeah, the tank's in a greenhouse and the 3 160 watt lamps are
5 feet above and light the entire greenhouse too"), but if those three
lights are going right into a 35 gallon tank, you've got too much.  Try
switching to a single 160 watt bulb, and use the other two when you buy
that 90 later. :)

  - Erik

Erik Olson
erik at thekrib dot com