# Lighting as it relates to growth rate



## iris600 (Feb 12, 2004)

I have a 20h that I am running a 60 watt coralife 6500k setup on (on the legs). I use the EI system, and my switch to that fert regimen has taken care of my hair algae. I use a inline Co2 reactor on a pressurized system gh11 kh12 ph6.8.

I have problem with some of my plants, such as glosso and the R. rotundifolia, getting lanky. With the R. rotundifolia, it is more of a longer internode length. 

Other plants still aren't growing as fast as I know they can grow. Do you think that in a densely planted situation 3wpg with a light system on legs may not be enough? (lights are about 6 inches from tank top using coralife black legs).

If I add additional lights, to get to 5 or so WPG, will I need to up the ferts even though I use the EI system which is should ensure that the plants have more than enough nutrients?

On my ten, which uses more WPG, I get faster and less lanky growth, but I have green algae on the glass.

How much do you think additional wattage will help this tank? I realize that it being a high tank, it takes more to penetrate the depth of the tank.


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## defdac (May 10, 2004)

The growth pattern (vertical/horizontal) is controlled by differences in the far-red-portion of the spectral distribution. When plants get shadowed by other plants the light is radically different and you seem to have gotten either alot of shadow or bad bulbs with the wrong type of light.

Som bulbs are known to trigger vertical growth such as the old GroLux-bulb, and some are know to trigger horizontal growth like Aquarelle/Aquastar/Triton.

Now, those bulbs have radically different Kelvin but that is not what you are looking for. You will look for nuances in the far-red portion and you will not know what to look for and probably can't look for it as the manufacters spectral distributions are very unexact, so the rather boring tip is to change bulbs until you get the growth-pattern you like.

It's not about WPG as you've noticed, see page 22 here:
http://www.cc.jyu.fi/~aphalo/old_pages/pdf/notes1.pdf

You can have high-light (HL) and get vertical growth if the light has "wrong" R:FR-ratio.


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## iris600 (Feb 12, 2004)

Would those brands of bulbs that you list as good for horizontal growth be something that could be used in a PC fixture (I am not familiar with those brands??)
Also, I see pictures here from many users where glosso creeps along the substrate,.. but mine grows straight up. It looks healthy, but it grows straight up instead of along the substrate.

I assume that the kelvin doesn't truly affect the growth habit as long as it is within the plants usable range (I use 6500K)?


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## defdac (May 10, 2004)

I'm not familiar with PC:s but I'm sure you can get a zillon answers on what bulbs folks think you should choose that is capable of pushing down all the plants.

Let's hear what PC-folks have to say.



> I assume that the kelvin doesn't truly affect the growth habit as long as it is within the plants usable range (I use 6500K)?


Kelvin is like saying the bulb has color "100" and you can reach that number by adding/substracting/multiplying a lot of different numbers (representing all kinds of colors) to reach the number 100. So you can't really say anything how the bulb will look or function just by stating the temperature.


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## AaronT (Apr 26, 2004)

Are you using a glass top on the tank? If so, cleaning it well and/or removing it will help to get more light into the tank. Glosso should be able to stay horizontal with that much lighting. What planting technique did you use?


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## iris600 (Feb 12, 2004)

Nope. It's open top. All my tanks are open top. I do have high gh/kh? Could that affect the growth?
Everything else (water condition wise) is within normal parameters. Fish are healthy.


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## defdac (May 10, 2004)

AaronT said:


> Glosso should be able to stay horizontal with that much lighting.


That is contradicting everything I said.

As you see you can have extreme lighting and if the PR:R-ratio is wrong you will not get horizontal growth.


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## AaronT (Apr 26, 2004)

Iris, how did you plant the glosso?


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## iris600 (Feb 12, 2004)

I planted it by seperating the plantlets into one or two node sections. I then used tweezers to stick the glosso into the substrate (in my ten it is eco-complete, about 1.5 years old, the other is turface, about 3 months old). 
I just want to figure out how I can fix this, and why some growth rates on toher species don't seem right as well (high internode length).
How do I figure out the r-fr on my bulbs? On the turface tank, it is a coralife bulb, 6500k, that others here have used with much success.


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## AaronT (Apr 26, 2004)

How old are the bulbs? After about 12 months bulbs are not as effective, though they will still burn.


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## iris600 (Feb 12, 2004)

On two tanks the bulbs are brand new, one is the commercial fixture with legs, the other new one is 6500K shoplight setup. The other lighting is older. It perplexes me.


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## iris600 (Feb 12, 2004)

On two tanks the bulbs are brand new, one is the commercial fixture with legs, the other new one is 6500K shoplight setup. The other lighting is older. It perplexes me.


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## youjin (Apr 1, 2006)

hi...your PM box is full....i am trying to send you a PM.


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