Lighting is very complicated...!

[cchang]

After all the posts and threads I've read about lighting... I went out on a mission to improve the lighting in my terrarium, only to realize how complicated of an issue this is.

I stopped over at Home Depot only to realize that my current 15 watt fluorescent is brighter than most of the 20 and 30 watts available for lengths 18" to 25".  I tried to compare by lumens but my current 15 watt is 800 lumens (regular fish tank fluorescent) vs. 450 lumens (plant fluorescent by Phillips).  If I decide to buy a new ballast with larger/longer bulbs, there are 20 watt bulbs but they're still pretty dim (600 lumens for the plant fluorescent by Phillips) compared to my 15 watt.  Even the regular 20 watt is not up to par.  Maybe I should just get another 15 watt/800 lumens if I need more light?

The only 30 watt I could find that would fit my terrarium was the Gro&Sho Bright Stik by GE which I also find dimmer than my 15 watt.

Man is my head spinning....  

 

[swords]

Avoid those plant lamps! They are very dim in comparison with even a plain old cool white flourescent lamp. I know you're talking about the flourescent strips and not the funnel shaped screw ins but they really are worthless. They're getting your money based on having "plant" in the name. If you're at home depot look for the flourescent tubes in the neon orange sleeve with the word"sunshine" written in yellow letters (when you slide the bulb out it should say "GE Chroma 50").
These bulbs are great with a rating of 5000K and a CRI of 90 I don't know how many lumens as I don't ahev the packaging sitting here but they are plenty bright when new (I replace lamps every 6-8 months). In my 4 light units I use 2 sunshine and two cool white in my six lamp units I use 3s & 3cw.

Just my 2 cents!

Josh

 

[cchang]

Thanks for the reply swords...

How long are the GE Chroma 50's? I ask because many of the 30 watts that I found that were bright enough were 3" (too long for my setup).
Also, you mentioned you change them every 6 to 8 months... is that their lifespan or do they start to fade around that time? It seems kind of strange that a fluorescent would expire after such a sort period....

Thanks again...

 

[Tony Paroubek]

Fluorescent tubes will burn for years, but they get progressively dimmer with age. They begin to fade from the moment they are turned on. Life of a standard tube is roughly 7500-9000 hours. Their light output starts to drop off faster and faster as they age. To maintain good light output they should be changed when they are at 50-60% of their life used. Estimating 14hrs a day and 30 days a month = 420hrs/month. 6 months is being conservative and making sure your plants are getting as much light as possible. 8-10 months would still be acceptable..

Light output on a fluorescent tube is dependent on the amperage of the ballast, the surface area inside the tube and the phosphors used.

I have found a simple 2 tube 24" fixture fits nicely over a 10 gallon terrarium. It over hangs the edges a couple inches but that is fine because little light is produced at the ends of the tubes.
Tony

 

[cchang]

Just made a couple phone calls around to various Home Depots up here in Toronto and apparently they all get their fluorescent bulbs from Phillips... not GE.

 

[Tony Paroubek]

Colortone 50 is the philips equivalent to the GE chroma50.

Ultralume 50 by philips is also a very nice bulb that is a little brighter than the colortone

Or just ask if they have any 5000k or daylight type bulbs
Tony

 

[Tony Paroubek]

Just for kicks..

Chroma50 tube has a mean lumen output of 1870lumens 5000k 90cri
The GE Ultralume50 equivalent SPX50 2820lumens 5000k 82cri

both 48" 40watt T12 (1.5")

pricing..
chroma50 $5
SPX50 $11.50

Here is an example where Phosphorus used shows a big difference in light output

Compared to a normal coolwhite in 48" 40watt T12
2650lumens 4100k 62cri Price $2

Tony

 

[swords]

thanks for the bulb stats tony!
I've never found those ultralume 50s but I like the number of lumens they produce.

cchang (and others) the Sunshine/Chroma 50 tubes are available (in my area) from 18"/15 w, 24"/20 w, 48"/40 w sizes.

 

[Tony Paroubek]

Best way I know to get the Philips Ultralume or the GE SPX is from a lighting store. Chances are they will need to order them. Grainger does stock the GE bulb also I think.
Tony

 

[cchang]

Ok... now were rollin'.
I visited Philips' website and they don't have the Colortone 50 listed as one of their products but..... I found in their ALTO series:

F20T12/D
Initial Lumens 1075
Design Lumens 960
Kelvin Temp. 6500
CRI 79

Here's something else I stumbled upon regarding lighting stats and manufacturers:
http://www.thekrib.com/Lights/fluorescent-table.html

Charles

 

[Tony Paroubek]

Hmm perhaps they have done away with the colortone then..

That bulb looks good 6500k is on the blueish side of the spectrum but is just fine for plant growth.

One thing to remember as a bulb deviates from the 5000k sunlight point. CRI will go down (which is why it doesn't always apply to growing plants) Also lumen output rating will drop a little.

Would be worth checking against their ultralume line also. They come in 5000-6500k models but should put out more lumens. Whether the increase in price is worth it or not would be something you would have to decide.
Tony

 

[seedling]

Hey cchang,

I am also from Toronto, I had just checked out Home depot here myself found there selection very poor.T ry calling Rona, their is one across from the home depot on St. Clair.

Not sure if they have the lights you are looking for but I picked up some "day light" Gro lux compact flurescents from there, they are only had them in 20 wyatt but comes with a built in reflector,made by sylvania. They also had a nice seletion of 70watt hps lights.

 

[cchang]

Hmmm... didn't think of going to Rona. Will try when I get some time. Thanks Seedling

 

[Parasuco]

I live in Caledonia and I got my lights at home hardware... It cost me fifty bucks for the ballast, a Grolux bulb and a cool white...