Lighting Spectrum and Photosythesis - Page 5 - Lighting

Newt · 06-30-2008, 10:04 AM

I got it from the Philips site:
http://www.nam.lighting.philips.com/...f/P-5136-A.pdf

hedson_25 · 07-18-2008, 10:30 AM

it's such a good thread, i haver a question...
i have a 60cm aquarium and use a coralife 2x65 watt but my red plants never turned red at all...
i suposed it's enouht light for a 70 liter tank...
wich 65 or 55 pc lamps could help me to have red plants?
i have fertz and co2 presurised...
i have now just one 55 67k the other one is broken...need to replace it...

Newt · 07-18-2008, 01:44 PM

This link has 3 CF bulbs that would be good. However, I personally use the Philips PLL-950s and I find them a nice white light and the high CRI makes for good color rendition.

http://www.1000bulbs.com/Full-Spectr...t-Light-Bulbs/

The website has them as 5300K which is the older version. The new ones are 5000K.
Also, the CRI is 92 not 82. I have purchased some from this site and shipping was quick.
The price has gone up on all of hem recently............well, what else is new.

P.S. I'd like to visit your location. LOL

mats808 · 08-02-2008, 03:51 PM

Quote:

Originally Posted by Aen

Seems like Takashi Amano reccomends green light over blue and red.

Quoted from Aqua Journal:
In the tropical streams where aquatic plants grow, sunlight are filtered through many vertical layers of tree canopy. The upper layer receives as much as 25% to 100% direct exposure to sunlight. This is scientifically known as the euphotic layer. In the lower parts of the forest and streams below, where low light conditions occurs, this si known as the oligophotic layer where a mere 1-3 percent of light is made available to plants. This small percentage of light are filtered through the forest green canopy and reflected as incidental light, thus the natural wavelengths are dramatically altered. Aquatic plants have evolved millions of years to adapt to greenish light available to them. The NA-Lamp adopts a fresh green ulothrix fluorescent to reproduce nature's green irradiance wavelength in your aquarium.

Here's the spectral distribution of NA-Lamps.

So I guess land plants or those that get sunlight all teh time like red and blue, while those at the bottom and in water have evolved to make use of green better.

Hi Newt,
I've been reading this thread and have found it relatively interesting. I stopped keeping fish several years ago. At that time there weren't as many options. I used Triton bulbs 100% of the time to grow plants and I felt that they did a good job. This was over 6 years ago. People were starting to use compacts but at the time I felt like they were overkill. Metal hallides were also being used, mostly for reef tanks but also by some freshwater hobbyist....I felt that this was overkill as well. Now, I see the need for such lighting, especially with some of the stem plants that are being grown these days.

I've just starting keeping aquariums again and I'm amazed at all the different options. Just out of curiosity, in your opinion what is the best bulb to grow aquarium plants assuming a normal 48in. T12 shop light? I've noticed that you seem to like Gro-lux bulbs but I still wanted to ask the question. Also, what is your opinion on Triton vs. Gro-lux?

Lastly, can you please address the quote above? All the things you've said makes sense and is pretty much how I've viewed aquarium lighting for years now. Without thinking too much about it, Amanos quote also seems logical and makes sense. I would really like to hear your opinion of this quote.

thanks,
aaron

Agentkhiem · 08-02-2008, 08:42 PM

Newt,

After spending a lengthy amount of time online searching for documentation on what matters in plant growth, I'd have to say that your posts have given me a lot of insight. Now I understand what matters most.. thanks

.

Since your emphasis is to obtain certain bulbs with ideal peaks for photosynthesis, am I safe to assume that your reasoning behind it is because a household T8 15watt output does not emit enough blue and red (forgive my layman) for sufficient plant growth?

If that's true, then here's a more important question: Can you double a household T8 fluorescent in wattage, consequently doubling the intensity in the red and blue ends to compensate for lack of both? The reason I ask this question is because I would like to retain a conservative-looking temperature rather than a disco-ball tank with several colored bulbs.

Again, thanks for your informative posts! Please reply soon

If your answer is yes, then basically I'm going to get very strong Powercompact lighting to compensate for weak red and blue ends.

defdac · 08-03-2008, 01:32 AM

It isn't true that green plants prefer green light, and it is too easy to test with the range of aquarium bulbs the average/above average aquascaper have at home.

Change from a greenish/yellowish bulb like Osram Biolux to a blue bulb like Aquarelle/Aquastar/Trion/PowerGlo and watch how the photosynthesis explode.

If you spent any amount of time searching for PAR, PUR and such you will see that every photosynthesis action spectrum has a clearly marked dip in the green-yellow range. That is - such light is clearly much more innefficient than blue and red.

Also take a look at the chlorophyll sensitivity. No accessory pigments in the world will make it more efficient to transport light from to the chlorophyll than actually hitting it directly.

defdac · 08-03-2008, 01:34 AM

(The reason for Amano recommends his light with extra green is probably because it looks more natural. It has nothing to do with it being more efficient growing plants)

mats808 · 08-03-2008, 03:14 AM

defdac,
Like I said in my earlier post....I pretty much agree with most of what has been said by "Newt" in regards to lighting spectrum, photosynthesis, etc. I have been growing aquarium plants for over 20 years now so I really don't need a lecture on what plants need in order to grow.

I'm not saying that Mr. Amano is right or wrong. However, if you read his quote carefully you'll see that he is in no way talking about making the plants look more natural. He's talking about how very little sunlight (1-3%) reaches the forest floor and that as this light is filtered through the forest's green canopy and reflected as incidental light its natural wavelengths are dramatically altered. He also says that aquatic plants have evolved millions of years to adapt to greenish light available to them. The NA-Lamp adopts a fresh green ulothrix fluorescent to reproduce nature's green irradiance wavelength in your aquarium.

Because I actually read and understood Amano's quote I thought about it and it kind of makes sense. I would make one change and say that this might apply more to lower light forest plants (Cryptocorynes, Bolbitis, Microsorum species, Anubias, etc.) and not so much higher light plants. There are many different kinds of plants with all different kinds of requirements. If some plants like high intensity light while others don't why is it not possible that some plants could appreciate 'green light'? I think after reading the quote it's pretty clear that Amano designed his bulbs to grow plants and not for aesthetics like you mentioned.

Personally I think that sometimes "Amano" is overhyped but I must say that it does seem like he has put a lot of thought into his products and they seem to work quite well. In some ways his books as well as his products have created a kind of aquatic plant renaissance. I think it would be foolish to quickly pass judgement and assume that Amano's theories on aquatic plant lighting are totally wrong.

Now maybe this quote is outdated and Amano has changed his stance and is no longer making these bulbs because they suck. Or maybe this quote was taken out of context and so it is misleading. All I know is that the quote that Aen provided seems to make sense....although it is counter to the conventional view of aquarium lighting. And if Amano says it works that has to be at least as good as 'defdac' saying it doesn't.

So I guess my point is although Amano's bulb goes against what I thought was proper aquarium plant lighting I'm going to go out on a limb and say that it probably works just fine.

niko · 08-03-2008, 05:52 AM

Wow, what a long thread!

To anybody willing to practically experiment on how the light spectrum affects plant growth I strongly suggest getting some Giesemann Midday T5HO bulbs. Each bulb must have an individual reflector.

What you will immediately notice is the amazing color of the light. Cool, but bringing the reds and greens out.

Also you will find that you can use 1/2 the wattage of what you previously used and have not just the same growth, but better one. And I mean 1/2 the wattage of a CF, not only a fat T12 or T8 bulbs.

So far I've done about 10 tanks with these bulbs and every time the results are outstanding.

--Nikolay

Newt · 08-03-2008, 11:55 AM

Green light/green plants......hummmmm.

The Amano article doesnt really say that green light is better than red or blue, simply that plants have adapted to utilizing a portion of green light available to them. Diana Walstad has also made similar claims in her book. However, I have seen no scientific data to support this nor have I read anything to dismisss this either. A majority of my reading has been in the Jounal of Plant Pysiology and other related university studies.

Most bulbs (for freshwater use any way) have a green peak so you get your green light anyway. I like to avoid the large heavily weight green ligt as it makes the tank look unnatural and even gawdy (my opinion).
Here is the photopic curve showing plant action spectrum and the human eye sensitvity:

mats808: I really like the GroLux Standard and GroLux WS for dawn dusk lighting. The Standard has a great peak of red at approx 660nm which you wont find in most bulbs as the red phosphour they use is quite expensive. If you have shop lights then you can mix them with Philips 6500K (F40DX) available at Home Depot. I would also get some reflective mylar for the fixture. The cheapest place I know of for GroLux lights is www.saveonlighting.com
You'll most likely have to buy a box of six.

Agentkhiem: I dont think its possible to double the wattage of a bulb and if you could I'm not sure that would increase the peaks of red and blue.

Niko: Giessmann Midday T5HO are becoming quite popular and are great bulbs - and quite pricey for someone like me who changes out T12's every six months and all others annually. I will be converting to T5HO soon. I buy my bulbs in bulk so I have a number to go thru. I will still use the GroLux for dawn/dusk lighting. I will also use them in conjuntion with Aqua-Medic Planta T5HO bulb (bottom graph):http://aqua-medic.com/t5_bulbs.shtml