lighting help please

[flowergirl]

i'm new at all this and i am looking for lights for my tank and i found someone selling t8's with 6700k with a cri of 98 and other bulbs that are 5000k with a cri of 90.

i don't really know what all that means and wondered if someone could help me out please.

thanks for you time

[samsfishnchips]

Hi flowergirl :D

lets see,

T-8, is the size of the lamp, 1 inch in diameter

CRI stands for Color Rendering Index and is a measurement of the visual quality of light, or how something appears under a particular type of fluorescent lamp. The CRI of a lamp is based on a scale of 0 to 100, with 100 signifying how an object appears under natural daylight conditions. However, keep in mind that high CRI value may not necessarily mean the best coloration.

more info on fluorescent lamps (http://www.drsfostersmith.com/pic/category_summary.cfm?dept_id=0&siteid=6&acatid=287)

standard

Freshwater Planted Aquarium - Fluorescent and compact fluorescent bulbs are frequently used to provide the full spectrum range of light (5500°K to 7500°K), most plants require. As a general rule, provide between 2 and 5 watts per gallon.


Saltwater Reef Aquarium - Many corals and invertebrates have naturally adapted to bluer light. Therefore, most reef lighting systems include bulbs with a high Kelvin rating. 10000°K to 20000°K are frequently used.

so in summary, T8 lenght determines wattage, the longer the more, like
18" = 15w
24" = 18w
30" = 25w
36" = 30w
48" = 36w

now you put the K, the lower the more yellow, the higher the more bluer, what you want to light? if its whats on your sign. I would stay away from that lighting, for reefs, stay above 10k, for best look, anything lower and it looks like pee ;)

good luck,

sam

[flowergirl]

well thanks for clarifing all that sam. i guess i don't want my tank to look like it's filled with pee now do i..lol! i guess i'll keep looking

thanks again