Newt

Yes, they do grow plants well. I have used them and many people use them and like them a lot. There is a good 'sticky' thread on the 9325 bulb in this forum.

What other CF's have you tried?

PiL

wow excellent thread... it's about 3 years since the last response!

anyways... having trouble finding info about 20k tubes. i wonder if you got any info in that scrapbook of yours on the subject, newt.

hope you guys are still alive!

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.

nemenem

Great thread this!

Does anyone know where to find the spectrum data for power compact fluorescents?

I bought a light hood that came with two generic CF 24W 10,000K bulbs in it (so I was told), photo:



Light hood is about 35cm long. The problem is that my red plants have all turned green and glosso is growing vertically, despite high CO2 levels, good water quality and good fert routine. At over 6W per gallon there should be plenty of light......so I have put it down to the output of the bulbs themselves.

Any help would be greatly appreciated,

Thanks.

hoppycalif

You apparently have about an 8 gallon tank (48 watts giving 6 watts per gallon), so the "watts per gallon" rule isn't of much value for that size tank. Looking at the photo of the light fixture, it looks like there isn't room in there for much of a reflector. If that is true, the bulbs aren't supplying as much light to the tank as an AH Supply light kit, with it's great reflector would. The fixture is also mounted on legs, higher above the water than a standard, rest on the tank, light would be, which also reduces the amount of light the plants get. I suspect that with that fixture you have moderately low light intensity now.

nemenem

Thanks hoppycalif, appreciate your input.

The tank is actually only 7 gallon, made a mistake in the conversion from litres, which makes it 6.8W/gallon. The hood sits about 8cm above the surface of the water, and is mirrored internally. I understand what you are saying about the reflector though, which is about 50% blocked by the lamps themselves.

If anyone could give me some data on the available CF lamps I am looking for it would be fantastic.

ZakkWylde

Nice read Newt, appreciate it. I took botany 2 years ago and we never really got down to the nitty gritty of light and photoysynthesis unfortunately.

gotcheaprice

I'm studying photosynthesis in AP bio right now I'll read up on this post when I have free time. This week is a crappy week xD (SAT SUCKS!)

Tentacles

I have 2 x 20W dayglow flourescent tubes over a 2ft cube, 6700k, and I was complaining about visible penetration to the depths, but from what I can see in this thread, the green light should be the most penetrative.

The shop I got the light from said all I could do was buy an actinic tube to put in. I'm not sure what this is... I suspect blue light?

Personally, I'm thinking of buying another light and running 80W above it and possibly getting the red end of the spectrum working with different tubes as well.

It's a NPT with low light plants, so it's not all about rapid growth.

hoppycalif

Don't bother getting the actinic tube for a planted tank. Actinic tubes don't produce light that is of much value to the plants. If your tank is 24" x 24" x 24", it holds about 60 gallons of water, and you only have 40 watts of light over it. That isn't enough to grow any plants in good health. Even low light plants need more light than that. 80 watts would just about be the minimum for low light plants.