Lighting Question

[daniel_koch]

I have a 30 gallon tank with a 24'' 20 watt florescent light bulb. everything works fine but the tank looks dark, im sure it doesnt help that i have black gravel in the tank but its what i like, the tank was used and i got it from a friend and i have not changed the light since i bought it off of him, my question is what kind of replacement bulb should i buy so my tank will light up better, i know WalMart has and 20 watt 24'' replacement bulb for aquarium purposes but if that wont make my tank brighter it would be a waste of money since mine does work.

Thanks
Daniel

 

[Mikaila31]

Getting a new bulb would probably help somewhat, it depends on how old the bulb is. Florescents do reduce in the amount of light the send out as they age. This is usually noted by a darkening of the ends(or base) and sometimes bands form on the light. The older/more used the light the larger these areas are. Below is a picture, its not the best as the two lights are different kelvin rating. The one on the left is suppose to be pinkish. The one on the left has been used for a few years and shows some very visible darkening and banding. While the one on the right is 3 weeks old. If you want a nice bright light, I would go to a home improvement store and just buy the same lenght/wattage bulb that is between 10,000-18,000K. If you have any other fixtures that use the same bulb, you can hang on to the old bulb since it still works.

 

[daniel_koch]

Thanks



What difference does the "K" makes i see from 6,000k to 20,000k is this the color the light give off?

 

[Rooster]

Get a reflector if you don't already have one, then try another tube - they are all different colours, you may need to try a few before you get one YOU like
If you have plants - make sure its a plant friendly tube...

 

[OldMan47]

A properly specified K rating is a rating that tells you how hot a thing would need to be to emit light in that color spectrum. Noonday sun is about 5000K to 5500K in color so a bulb of about that temperature should give a spectrum that resembles daylight. Salt water reef people prefer a light of 10000K or more to better resemble the spectrum at some depth below the water surface. The longer wavelengths get absorbed more than the shorter wavelengths by the water so sunlight at depth in the ocean will be bluer than at the surface. The spectrum of a typical warm white or cool white fluorescent tube is around 2700K to 3000K. All of the bulbs at 20 watts will emit about the same amount of light but the 6700K or higher bulbs will seem brighter to your eye.

 

[Mikaila31]

If you are using something similar to the fixtures I posted, they have white plastic reflectors. You can improve these by hot gluing/epoxying tinfoil over them. They will reflect the light better. A real reflector would be best, but tinfoil is a cheap fix.

 

[daniel_koch]

my lighting fixture is old and alot of the plastic reflector is broke off how can i go about replacing the whole reflecting area

thanks