[timoj32]

I recently purchased a 125 gallon aquarium. I decided to use 48" shop lights for lighting until I am able to purchase something more appropraite. When I was picking out the flourescent tube lights I bought the regular cheapo residential 40 watt GE Ecolux lights. I used these lights for serveral weeks before I realized there are 48" "Plant & Aquarium" lights made by Philips that are also 40 watts. Once I replaced the GE lights with the Philips lights I noticed a huge color difference in the lights. The GE lights give off more of a white color while the Philips lights give off more of a pink color. I myself like the white lighting better then the pink.

Now the question. Is one light better than the other for fish, for plants, for whatever or does it just come down to owner preference?

 

[gunnerx]

The Plant & Aquarium lights are most likely 6700k. My Coralife freshwater T5 6700K is that slight pink/purple colour. If you have plants in the tank, the 6700k will most likely make more of a difference. However, if you would like to showcase the fish more and have minimal plants, then go with the white light.

 

[BillD]

The Philips plant and aquarium lights are not 6700K, but around 4200K, which is part of the reason form the pinkish light. It is a mix of spectrums, but has a very low light output. Around here Home Depot sells 2 packs of Philips Utra Daylight tubes , 40W for $5.99. They have a much better light output, and a colour most people like (very white bordering on blue).. My preference is for the Philips Natural Sunshine (5000K) but I use both.

 

[gunnerx]

Ah, good to know! Isn't 4200K a bit low for plants?

 

[bulldogg7]

The Philips plant and aquarium lights are not 6700K, but around 4200K

ditto around 3500-4200
Look for 6500k for white light, maybe higher, Lowes/Homedepot sell these, just takes a while to read all the labels. Phillips makes a 6500k bulb, it's brighter than the GE brand, but degrades alot quicker. I had both on my tank for about 6 months, after around 4 months the GE ended up brighter and whiter. The phillips 6500k looked awesome for a few months, but the GE outlasted them. Lowes carries GE, HomeDepot has Phillips, at least that's the way it is around here.

Yet the funny part is Lowes doesn't carry GE 6500k compact fluorescents, only Sylvania. And they have only Advance ballasts.
Home Depot carries GE ballasts but not bulbs, at least not the kind you'd want.
:roll: :-? :roll:

 

[star rider]

the XXXX K number is the reading in Kelvins and is really a measure of temperature.

your best bet is to look for daylight bulbs that will give you full range spectrum if you are looking for light for plants.

lum and PAR are usually7 considered more important.
(light for planted aquariums is kind of complicated.)

 

[timoj32]

Thanks for all the great info. I think I will go back to "white" lights because I don't have a lot of live plants.

 

[justshoe]

Just picked up the philips 6700k bulbs Very white with just a hint of blue

 

[Narwhal72]

When discussing lighting Kelvin refers to the correlated color temperature of a light source in relation to a theoretical black body radiator. This is based on Planck's law. Starting at 5000K the color will be basically white with a tint of yellow, change to pinkish through 6000K and turn to blue beyond 10,000K.

Full spectrum refers to any bulb that produces light in all visible wavelengths between 400 nm and 700 nm. This does not refer to the color of the bulb. A 10,000K and a 6500K are both full spectrum bulbs but they are not the same color.

PAR (photosynthetically available radiation) is the major criteria for growing plants or other photosynthetic organisms (corals). This measures the total photonic light output between 400 and 700 nm.

Lumens measures the amount of light output relative to human vision. It is weighted towards the higher end of the spectrum as this light is more visible to the human eye than wavelengths at the lower end of the spectrum near 400 nm.

A bulb may have a high PAR value but have a low lumen value. A good example is an actinic bulb. These have high PAR values because they produce a lot of light between 410 and 470 nm where chlorophyll a absorbs energy at it's most efficient. But they have very low lumen values because the human eye cannot see light below 400 nm and these bulbs are very close to that theoretical border.

It is often a good idea to blend different types of bulbs as it is often difficult to get perfect lighting with just one bulb. However if you are limited to just one bulb and you are not trying to grow plants or any other special purpose just get whatever bulb you like best. It all comes down to personal preference in most cases.

Personally I like a little actinic blue with my fish blended with 10,000K.

Andy

 

[D-007]

Yet the funny part is Lowes doesn't carry GE 6500k compact fluorescents, only Sylvania. And they have only Advance ballasts.
Home Depot carries GE ballasts but not bulbs, at least not the kind you'd want.
:roll: :-? :roll:

So go to Lowes for the GE bulbs and Home Depot for the GE shoplights ... right?