Duro-test Bulbs and Trimming Plants

Subject: new lights by DURO-TEST
> A question for all the lighting experts out there. I just
> received the spectral analysis for the new Aurora V from
> Duro-Test(vita-lite) and I wondered what the opinions on it
> would be. Let me start by saying in 3 foot it has 50% more
> lumens than a vita-light. 2400 compared to 1600. The ultra-
> tri-lux is 1880. The CRI is 85 and the temp is 5000k. They
> describe it as sunlight-simulation. Ok then, there is 3
> major peaks and one minor. The first peak  is at 420nm is
> about 50%, next at 490nm is at 30%, next 540nm is 100% and
> the last is 605nm and 90%.. The percentages are of max light
> Looking at other spectrums for other bulbs, this appears to
> be good combo,maybe a little too red. Good for plants or not

It's hard for me to tell without _Seeing_ the spectral graph, but 
my instincts tell me that VitaLite has always been a good bulb, 
5000K is right, and the lumen output is good.  I'd certainly give 
it a try if the price was right.


Subject: PL-L CF, trimming stemmed plants

>     This is my first letter to the list, though I've been lurkin
> weeks now.  Anyhow,  I have two questions for everybody.
>     One, I was looking for a cheap way to increase the lighting 
>  I have a 52g hex flatback, which makes it a tad difficult.  I c
> two 4' striplights (4 bulbs) with a mix of cool whites and growb
>  Unfortunately, I have driftwood which is leaching tanins into t
> makung it quite dark.  I rather like the brownish water so I wou
> increase the light going into it.
>     I was looking in the Grainger's book and saw 50watt PL-L com
> flourecent bulbs.  They are 22.5" in length and but out 4100~420
>  The only problem is that the color is in the 3k~3500 range.  Th
> I'm interested in these buls is that they can be powered by a st
> electronic flourecent ballast.  They are basically short 4' bulb
> anyone know if/where I could get a hold of a warmer bulb?  By th
> some calculating and found that this bulb also has a higher lume
> than the lower wattage CF bulbs.

There's nothing worg with using a lower K bulb to boost the total 
lumens available on your tank, but I really think you'll get 
better results by removing the discoloration from your water.  If 
you can see it, it's cutting out a lot of light to your plants.

>     My second question is how I should go about trimming by stem
>  I have Cabomba Carolinia(sp?) and M. Aquatica (sp?).  They grew
> when I planted them, which coincided with a large water change (
>  They are at the surface and sending shoots from variuos nodes. 
> aquatica looked great at first, but since the water has darkened
> of the leaves have died back.  The cabomba is growing with large
> between nodes, which I assume means a lack of light.

It's typical for both Cabomba and Milfoil to grow quite quickly in 
the beginning, even under abysmal conditions.  They are just using 
up stored reserves.  You could be seeing the results of a lack of 
light, or it could be a CO2 deficiency if you don't supplement 

The usual way to trim stem plants if the bottoms get unsightly is 
to remove the bottoms and replant the tops.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA