[niko]

Ok, here's the spectrum of T5HO Giesemann Midday fluorescent bulb. A bulb that produces light that is both very good for the plants AND has a color that is just beautiful to look at. If in the middle of winter you place a 54Watt Midday bulb in a room, get out of the room, and look at the open door you wil swear it is summer in there - beautiful sunlight spilling out the door:

Now look at what are the best wavelengths for photosynthesis:

Chlorophyll A: 435 - 665 nm
Chlorophyll B: 490 - 650 nm

Apparently the Germans have almost completely ignored Chlorophyl B. But they have added green color to the bulb (more or less useless to plants) I guess to make people like me like the color of the light.

So, what can you tell me about that situation? Why that bulb seems to grow plants very well?

I am aware of the fact that the photosyntesis runs just fine at wavelengths "close enough" to the perfect. 430 or 440 is fine, 660 or 670 if fine. Ok, good, but is there anything else that I don't know?

 

[Newt]

Niko, I used to work for Sylvania and very few fluorescent bulbs get above 625nm. The true red phosphor is very expensive. The Sylvania GroLux, a T12, outputs in the red right where you want it.A handful of other bulbs (some may no longer be made) use this phosphor. But being a T12 you loose much of the punch and they lose 60% of their strength in six months use. I still use the GroLux Std and Wide Spectrum as dawn/dusk lighting - I just like the look. Also, I stage my lights both on and off.

The Midday to me as a stand alone bulb is the pits as far as color goes. Each to his own. Giesemann recommends it be used with the Aquaflora; which is what I do. It balances the color to more of a white light. If I look at the fixture while ON with the Midday, Aquaflora and an Aquarelle the Midday looks green.

 

[niko]

Newt,

Do you happen to know something about the Emerson effect?

http://en.wikipedia.org/wiki/Emerson_effect

I just read on "some" forum that if "certain plants" receive 710 nm of light the last few hours before shutting all lights off they go to sleep much faster. The people growing the "certain plants" are interested in the blooms. There was a reference to some info that the plants go to sleep up to 1-1/2 faster.

Interested in blooms or not, getting faster to the dark cycle of the photosynthesis should mean much more bulk mass accumulated, right? Basically the plants will grow faster.

Does any of that translate to aquatic plants?

 

[niko]

Also, look at the Giesemann AquaFlora spectrum. Same thing - missing wavelengths that are good for the plants:

And if we look at pictures only it looks like the AquaFlora is actually worst for the photosynthesis than the Midday. I think I'm really lost now. This red phosphor must be way pricey in Germany if they just flat out refuse to use it in a bulb they call "AquaFlora".

 

[Newt]

I have not heard of the Emerson Effect but thanks for the link. I will read up on it. I have read that light too far into the red (infra-red) will shutdown photosynthesis. Not sure if this is true for all plants. I used to do a lot of reading on University studies in the Journal of Plant Physiology. Now I'm married with children.

My mentioning using the Aquaflora wasn't because it had light output at the correct nm but because it augments the Midday more color-wise.

The only T5HO, or T5 for that matter,that I have seen that has red at 650nm is the Fiji Purple (attachment below). I'm not sure you'd like the color of it alone. You would have to color balance it with a bulb that has lots of green. Something in the 5000K area.

I would say the Giesemann bulbs are there nanometer wise for the blue light but don't make it for chlorophyll A in the red by a lot.

I have some lighting gifs in my albums section. Click on my User name and go to View Profile. Look on the right side for that album.

 

[niko]

Wow! Nice! I will look them up!

I just found this gizmo:
http://makeprojects.com/Project/High-Res+Spectrograph/658/1

How good do you think it will be?

I'm asking because all this reading about specs of this or that bulb goes out the window if you have a piece of (possibly dirty) piece of glass in front of the bulb. It'd be nice to be able to take an actual spectrum reading.

 

[niko]

Well, I see that the GroLux blows them all away if you want a single bulb to provide al the wavelenghts that the plants like.

I understand now what's the big (and rather ridiculous) fuss about building expensive LED fixtures to grow "tomatoes" and "pansies". There isn't much choice of correct spectrum bulbs. And the GroLux probably runs hot which for "tomato and pansies" lovers is not safe. Geez!

I think I learned a few things about lighting for plants today.

 

[Newt]

A while ago someone here was building an underwater spectrograph. I think he was a member of the DFW Club. Did it ever pan out?

I think Reef Geek and/or AquaCave sells the Fiji Purple. I look it up and post a link.

 

[Newt]

Reef Geek
http://www.reefgeek.com/lighting/t5-fluorescent/bulbs/korallen-zucht-kz.html

AquaCave
http://www.aquacave.com/KZ-Korallen-Zucht-T5-High-Output-Aquarium-Bulbs-C330.aspx

 

[niko]

Wow, this is worth experimenting with!

Thank you!

 

[Newt]

Well, I see that the GroLux blows them all away if you want a single bulb to provide al the wavelenghts that the plants like.......................

The wavelengths hit the right spots but when viewed on a normalized plot then you can see that T12s put out about half the 'strength/intensity' of a T5HO. The Fiji Purple is ridiculously strong.

 

[AaronT]

At $30 a bulb I'll let Niko do the experimenting. I'm having a hard enough time forking over $20 a bulb for the Giesemanns.

Looks like you can get the Sylvania GroLux T5s in other countries.
http://www.aquaristikshop.com/e_Produktinformationen/Sylvania-Gro-Lux-T5.htm

 

[Newt]

The T8 and T5HO versions of the GroLux, available in other countries, do NOT have the same spectral output as the original T12. Not even close.

 

[niko]

This fluorescent bulb talk is all fine and dandy, but look at this:

http://www.ebay.com/itm/90W-FIVE-BA...614?pt=LH_DefaultDomain_0&hash=item27ccd0f436

Look at the graph. Them tomato&pansies growers target the wavelengths: "... Wavelength: Red=640nm to 680nm, Blue=450nm to 460nm, Orange=630nm..."

What do you think I save Aaron even more money?

And if the KorallenZucht bulb needs to be used with others because of the ugly color I shudder to think what bulbs I need to use with that UFO light to make the light pleasant to the eye.

 

[AaronT]

Haha, I've used those cheap LED grow lights from Ebay before on my emersed setups. They do work, but the plants look brown and dead under the lighting. It's hideous.

 

[niko]

I have one of these mixed LEDs circuit board with the ugliest light color you've ever seen. But it is only 14 watt. The plants look astonishingly ugly under it. I got it 4 years ago and used it only once over a single emersed crypt placed in the middle of a 10 gallon tank. The crypt grew but I never wanted to look at it, the light made it look disgusting, you are right.

http://homegrownlights.com/14wled.html

I see that the wavelengths are not bad at all:
"..204 Red (615-655nm)
68 Blue (455-485nm).."

The 14 watts are not enough for anything but illuminating 1/3 of a 10 gallon tank (and I'm not sure if it will go through the water column very well either). I start having the feeling that wavelengths are all good but the light also needs to have a "punch", or intensity I guess. I even wonder if the cheap LED Flood Light that seems to work very well used together with a Giesemann Midday does exactly that - provides the punch, but the Giesemann provides a more or less good spectral range of wavelenghts. As I mentioned in the thread about the LED Flood light - when I turn the LED off the pearling stops (the Giesemann by itslelf is not enough), but if I leave the LED Flood on and turn off the Giesemann the pearling is reduced about 25-30%. It's almost like the 2 lights help each other in some way.

I now wonder if the 14 watt "old school" LED actually works better than I think. Especially if used in conjunction with a more powerful light. I will see if I can mix its ugly, ugly light with a bulb that will make the color ok. If I can figure this out maybe I will shell out $100 for a UFO light sold by a seemingly shady e-bay character and advertised by a silent girl in short mini skirt and flip flops. The same place sells "dance poles", I may get one too and save on shipping, hahah

 

[tefsom85]

Haha.. I was looking at the ebay link for the UFO light. It states "1) No HEAT SIGNATURE detectable by infrared cameras." I'm sure this is important for growing tomatoes somehow, right?

 

[AaronT]

Have you tried the new ZooMed bulbs made in Germany? I'm using them on one tank and they grow plants well. The color is pretty close to the Giesemanns and half the price. I mix the ultrasun and florasun bulbs 50/50. Kensfish.com has them for $9, $10, and $11 each for 24 watt, 39 watt, and 54 watt bulbs respectively.

The spectral graphs of the two compliment each other nicely. Click on the "More Information" tab.
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+3733+8066+4479&pcatid=4479
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+3733+8066+4489&pcatid=4489

I wouldn't mind trying the GE starcoats either. You can find bulk deals to split with friends at like $5 / bulb.

 

[Michael]

Aaron, those are an attractive option if used with good reflectors. How would you compare their output to T5 NO and HO tubes? And what fixture are you using them in?

 

[AaronT]

Aaron, those are an attractive option if used with good reflectors. How would you compare their output to T5 NO and HO tubes? And what fixture are you using them in?

Rereading my post I didn't articulate myself very well. ZooMed makes these in T5HO sizes. These are the ones I was referring to that I use that Kensfish carries. I just couldn't find the spectral graph for them so I linked to the T8s as they are the same.