Need fluorescent light equivalent to nano LED fixture

morainy

Subscriber
Mar 12, 2010
10
0
1
Vancouver, B.C.
Hi Everyone,
Please excuse this confusingly-titled question.

One of my sons has to do a science assignment over the next few weeks. It's not a full-fledged science project but it's still an interesting project. He is going to compare the growth of a few different plants in 2 nano Fluval Spec tanks, one using the 31 LED Spec light (or 2 of them), and the other using a fluorescent light with similar lumen value (and kelvin value, if we can find it). He wants to find out how the plants (mostly green, one red) respond to LED versus fluorescent light.

I can't figure out how many lumens the Fluval Spec's light is, and it turns out that different light emitting diodes have different brightnesses, so just counting the number of LEDs won't help.

Does anybody know how many lumens are in a 31 LED Spec light? (I asked at the store and they didn't know, and I couldn't find this info on the Fluval website) Can anybody suggest a fluorescent bulb that might be similar? (eg. 7 watt...)

I know that there are many other variables that he won't be able to control for -- the kelvins won't be the same, for example. But it doesn't have to meet science fair criteria, only offer him some chance for observation and fair comparison.

In addition to finding a bulb for the second Spec, he would appreciate a link to some information about how different kinds of light affects plants (different kelvins or spectrum or types of diodes, probably, not low light versus high light).

After he finishes this project, he will donate one of the tanks to the school, so it will have a happy outcome no matter what.
 

morainy

Subscriber
Mar 12, 2010
10
0
1
Vancouver, B.C.
If anyone can help me figure out the lumen value of a Spec nano LED, I'd be thrilled!

Hagen/Fluval has still not been able to tell me the lumen value of their 31 LED nano Spec light. They're working on it.

I have to get a light for my son that will be equivalent to either one or two of SPEC's lights by tomorrow, for his science assignment. It just has to be comparable enough to make comparing plant growth between them scientifically valid at a class level (not the level of a full science fair assignment). I'm guessing that a 7 watt light would be similar... but I don't know. Maybe a 30 watt light, if it's one watt per LED?

I hope that someone can help me! Thank you.
 

Gerryd

Plant Guru Team
Lifetime Member
Sep 23, 2007
5,623
22
38
South Florida
Hi,

The only IME accurate way to measure the lights the plants receive is with a PAR meter. PAR can be measured across ALL types of lighting...

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

I do not think that a strict lumen and or temp rating (6500, 10k, etc) comparison will be accurate....esp not across different type of lighting.

http://www.apogeeinstruments.com/quantum/?gclid=CMnwhYGQua4CFQpS7AodgGzFPw

http://www.licor.com/env/pdf/light/193SA.pdf

Is there a local fish club perhaps that you can contact to see if they have one you can borrow? =

How about a rental??

http://www.globeaqua.com/rental_par_meter.html
However, you cannot IMO run a comparable setup w/o the same light values...it makes too much of a difference in growth rates (assuming c02 and nutirents are provided in sufficient quantities...

Hope this helps.
 
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morainy

Subscriber
Mar 12, 2010
10
0
1
Vancouver, B.C.
Thank you, Gerryd!
I am a member of a local online aquarium community, and so I might be able to take the lights over to someone's house and borrow their PAR meter, if I bake a batch of cookies to go with... But, I'm not sure what kind of light to buy, to start with? It'll be at least a couple of hours on the bus to test lights, so my son should take a range of them.

I was thinking that the Spec lights are quite low in light, so maybe a 7 watt fluorescent? Or what about one of those tiny Marina betta kit lamps, which are essentially chandelier incandescents? I have those.