Hydro Culture HPS Lamps

bennyss

Junior Poster
Aug 5, 2005
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Hi,
There is specific Hydro Culture HPS lamp specific for plant grow.
For example Sylvania Grolux Philips plantStar.
These lamps have added blue light compared to standard HPS lamps.
Did anybody use these lamps for planted aquarium?
What is your opinion?

Regards,
Benny
 

defdac

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Re: Hydro Culture HPS Lamps

The problem with plant-bulbs is that nothing is added, just removed. To get more blue and red they filter out yellow-green. Energy loss. Nothing gained but uglier light.

You can calculate how much of the energy you put into the bulb is converted to ordinary human light, lumens. This gives you an efficiency how well the bulb produces photons in the human visible range. Together with the bulbs spectral distribution and a photosynhtesis action spectrum you can then calculate how many photons from the bulb that do good to plants. You have then calculated the Photosynthetic Usable Radiation efficiency. PUR-efficiency.

Sylvania GroLux has a PUR-efficiency of around 0.5 microE/Joule, compared to for example Philips Aquarelle (TLD89) with a value around 0.8 microE/Joule. I have calculated values for a couple of bulbs:
http://www.defblog.se/permalink/1402.html

Another take on this is that some bulbs only loses about 10% of its initial output intensity, GroLux/plant-bulbs are not included. But tri-phosphors like Triton, Aquastar, Aquarelle are.

All this is of no special importance when it comes to getting a nice planted tank especially not if you can afford the extra electricity and bulb-cost. With EI and good CO2-levels you will not find the light of any significance at all because you will manage to grow everything rather fast with surprisingly low light intensities.

But if you want to grow a plant faster than anyone else in some sort of growth-rate-competetion, PUR-efficiency would come into play. If you have an action spectrum for one specific plant I can tell you which bulb will grow that plant faster than any other bulb.
 

Cornhusker

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Jan 23, 2005
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Re: Hydro Culture HPS Lamps

:) defdac, what is your opinion of the vita-light?i have one,and one factory fixture issued bulb over 20 gal long,for over 2 years and seems like crypts really grow good under this light,with no co2. regards,cornhusker
 

defdac

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Re: Hydro Culture HPS Lamps

I would need the spectral distribution and lumens-output to calculate the PUR-efficiency for it. Will gladely add it to my list if you find it!
 

Tom Barr

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Re: Hydro Culture HPS Lamps

Vitalites are old these days, back in the 1980's they were quite popular.

The HSP + blue are good for Hydro gardening but not good for tanks as they are quite yellow still.

I'd suggest a mix of 2 HPS and 1 MH instead of mixing them in one bulb for hydrogardening.

Just get the MH 5000-10000K bulbs and you'll do well.
Regards,
Tom Barr
 

bennyss

Junior Poster
Aug 5, 2005
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Re: Hydro Culture HPS Lamps

Tom Hi,
Thanks for yout reply.
I have MH 400W lamp and the Sylvania GroLux HPS lamp.
I found that regarding to pearling and CO2 consumption the HPS lamp is giving much better results.
My aquarium volume is about 80 Galons.

Is the spectrum of the HPS Grolux is much better than the MH lamp?
What do you recommend based on this resilts?

Regards,
Benny
 

defdac

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defdac

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Re: Hydro Culture HPS Lamps

Something went wrong when they did their datasheets because all three lamps have the exact same spectral distribution, two bulbs with different color temperatures cannot have the same spectral distribution.

The PUR-efficiencies calculated with the same spectrum but different lumens/wattages is 0.62 on the last two 150 watt bulbs, and 0.57 on the first 265 watt bulb.
 

Tom Barr

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Jan 23, 2005
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Re: Hydro Culture HPS Lamps

HPS bulbs do grow the plants very well, the problem is the color.
A little blue will help perahps some plants, but stomotal opening which is one thing that blue increases, does not apply universially to submersed plants, the CO2 can diffuse through many places as many aquatic plant leaves are only 2-4 cells thick(Myriophyllums, Hydrilla, Egeria, Najas etc............)

I'd not mind spending a few more $$ to have a nicer color.
The added red in HPS will help growth, but speed is not everything, the tank needs to appear nice to your eyes and the colors of the plants also need to appear aesthetic to us also.

5-10K MH lamps do this pretty good.


Regards,
Tom Barr