Metal halide - 10,000 k for corals

[MadAboutCPs]

Hi,

I have a 10,000k Metal Halide lamp and ballist that was used on a Marine tank for corals. I am wondering if this is suitable to use to grow Nepenthes in a lowland tank. How far should these lamps be from the plants because I didn't get a manual for it and it was custom made. And I don't want to burn the plants.

I am also using fluorescent tubes such as powerglo and I have seen the aqualux fluorescent tubes and they have 10,000k written on the packet and claims to promote growth for plants and corals as opposed to a grolux fluorescent tube that says it promotes photosynthesis. Which is the best to use and what is the exact spectrum (in nanometres)  that Nepenthes require to grow efficiently?

Thanks,
Christian

 

[agustinfranco]

HI mad about cp's.

I use 2 18,000K for my tanks. that will give them enough light.

Gus

 

[swords]

Hi Christian,
I put a 10,000K metal halide over my chamber and it looked pretty dim-not very intense-very blue. So I changed it out for a 6500K which is a far whiter light. I'm not saying it won't work, it's just designed more for corals who specialize in using the blue wavelength.

Tropical sunlight is 5000K and 100 Color Rating index (all the wavelengths). The Chroma 50s by GE almost exactly simulate tropical sunlight but I find them a bit too golden for my taste. Sun at the level of Chicago IL is 6500K is a a crisp white color. I use the "Daylight" 6500K bulbs, a twin tube pack at wal mart is about $9.25 compared to about $20 per tube at an aquarium shop for the same thing. You know you'll need more than the one tube right? I have six tubes over my terrariums lit by fluorescent tubes and this gives me a pretty intense lighting. I also cover the glass with tinfoil (with flip up flap on the front for looking at my plants) this lets the light bounce around "infinately" and not be lost to the rest of the room.

Hope that helps some!

 

[MadAboutCPs]

Hi swords,

Thanks for the detailed info. I gather using multiple fluorescent tubes such as growlux would be more beneficial to the plants. Is blue light required for plant growth and photosynthesis in plants and the red light for flowering?

And would placing cut to size mirrors around the tank to reflect light be more effective than foil used in cooking?

Christian

 

[Tony Paroubek]

Blue light (about 420-435nm) is the range chlorophyll A functions at. So you want a good portion of your spectrum at this wavelength since chlorophyll A is the primary molecule powering photosynthesis. Plants can also absorb other wavelengths via different molecules to help suppliment photosynthesis. Red and far red light play large roles in many plant processes and the timing of them. Flowering is one of them.

Sorry I can't help on the distance. It would depend on the bulbs output. I would deffinately start at a good distance though because switching from fluorescent tube to MH is likely to burn the plants if your not careful. Then decrease the distance over time until the proper distance is reached.

As for the 10k bulb you can use it although 5k-6.5k is probably better rounded. You could always add a second bulb in a small fixture.. something like one of those softwhite compact fluorescent bulbs (2.1k) would add red to the balance.
Tony

 

[swords]

Oh, no, don't mistake meto say use those "Gro Lux" bulbs!  If you're thinking of those "plant bulbs" they sell at most home stores they are very dim as well.To me they aren't much better than trying to grow with a hippy blacklight.

If you have a MH then most certainly use it it's the closest you can get to sunlight in your house. I just saying that I would use a different more balanced bulb. www.marinedepot.com sells MH bulbs in varying wattages and spectrums. Most are reef spectrum 10-20K but they do also sell 5000 and 6500K MH bulbs and thankfully these are also on the cheaper end of the MH bulb spectrum! I use the 400 Watt Ushio 6500K over my bathtub/showerstall intermediate (house temp) grow chamber chamber. It works excellent!

 

[homer]

Hello Christian,

Just the other day I bought a Coralife 20,000K 40w fluorescent bulb that promotes growth for plants and corals as well.  I emailed the manufacturer for more information, and found out that the CRI is 92, and total lumens is 2600.  Compared to the Chroma50 which is 90 and 2250.  

The Coralife is only 1 of 4 bulbs I have powering the terrarium, so it's impact shouldn't be too dramatic.  

Anyone else using 10K or 20K bulbs out there?

-Homer

 

[MadAboutCPs]

Hi tony, swords and homer,

I am really impressed with your plant photos Tony. They really gave me some inspiration.

And thanks for the assistance. I have been out in the garden re-arranging the greenhouse and inside getting the lighting right. I have a 68 watt metal halide lamp which is supposed to maintain medium size plants. And a powerglo fluorescent tube, a sylvania grolux fluorescent tube and a sylvania aqualux fluorescent tube. Am I giving these plants a broad spectrum or is it just overkill?

Thanks everyone,
Christian

 

[homer]

I think it sounds fine.  You'll just have to experiment and see what kind of growth you get.  Sometimes I have no 2 bulbs that are the same on my setups.

As for reflective material, I recomment mylar.  Check a local hydroponic store.

best of luck,

Homer

 

[Flip_Side_the_Pint]

hey Homer what are you talking about when you say the CRI is 92? what is 92 refering to? and are you talking about thier VHO or thier NO bulbs?

 

[Tony Paroubek]

CRI is color rendition index. Basically means if you put a color sample under the light and look at it, how close will it appear in color to the same sample in sunlight. While nice for looking at your plants because it is based on human perception of color, it means nothing for the plants growth. Lumens and color temperature are much more meaningful as far as the plants are concerned. Lumens tells you the amount of light while the color temperature indicates spectrum balance.

Christian I wouldn't stress the spectrum too much, as long as you stick around the middle somewhere. Much more important is the amount of light.

Tony

 

[superimposedhope]

I use a Compact flourescent 6500K and then accent with 4 different varying color spectrum bulbs. Basically cause I have them laying around.

Joe

 

[Spectabilis73]

May as well post this:

Quote[/b] (http://www.ahsupply.com/bulbs.htm @ June 15 2004,11:32)]
The Color Rendering Index (CRI) for all 5500K bulbs is 91-92. That's "excellent" in CRI talk. All other bulbs in the 5000K to 6700K range have a good CRI in the low 80's. A common Cool White fluorescent bulb usually has a CRI in the low 70's. That's considered "fair." CRI's below 70 are considered "poor." Note that CRI is irrelevant for marine setups when the aim is to simulate the appearance under many feet of water rather than to simulate the appearance of colors under full spectrum light. Blue actinic bulbs used on marine setups usually have a CRI in the 20's or 30's.

The difference between CRI 92 and CRI 84, for instance, doesn't mean that all colors are rendered with 8% less accuracy with CRI 84. It only means that certain colors that depend on the wavelengths that the CRI 84 bulb is lowest in will be rendered somewhat less accurately. It is likely that the CRI 84 bulb will supply all the wavelengths necessary to render all colors you are interested in very well. That's why a CRI in the 80's is considered "good."

A lumen is essentially a measurement of brightness to the human eye and is therefore very heavily weighted to the middle wavelengths of light that the human eye responds to most readily. As such, this measurement is not very helpful for aquarium applications since the middle wavelengths are the least important to aquarium inhabitants. To focus on lumens can be very misleading. For instance, the 55W 5000K bulb in the chart above has 4200 lumens while the 55W 6700K bulb has 4600 lumens. Yet these bulbs have the same total light output. The 6700K bulb simply has a little more of its output in the middle wavelengths.

 

[MadAboutCPs]

Hi guys,

There are so many factors for optimum growth. I am going to have to look into it.

Christian