View Full Version : kelvins or watts?? wats more important??
crazycanuck
03-28-2008, 4:26 PM
from what i have seen,you can get like 60 and 70 watt cfl bulbs,but the higher wattage ones have only like a 2,500 k rating.. should i stick with the 6,500 k bulbs that are only like 20 watts each??
1 ) 400 total watts at 2,500 k
2 ) 125 total watts at 6,500 k
the tank is 55 gallons and will be heavily planted
thanks :)
WinnipegDragon
03-28-2008, 4:39 PM
2,500 Kelvin will be very yellow. I would aim for the 6,500 Kelvin, and then worry about wattage from there.
livingword26
03-28-2008, 7:50 PM
400 watts of anything is way to much for a 55 gallon tank. It would be an algae factory. The 125 watts of 6500k will work great for mid light plants.
plantling
03-28-2008, 8:03 PM
The standard hoods can usually only house regular flourescent bulbs w/low wattage. If you upgrade to CF lighting you can get double or tripple wattage. I would shoot for around 2 watts per gallon and 6700k.
2500k is so orange, are you talking about hanging a 400W HPS over your tank? Don't do that. Please.
rich311k
03-29-2008, 9:54 AM
Choice 2 should work well. You can always add a second fixture later if you want more light.
crazycanuck
03-29-2008, 12:41 PM
2500k is so orange, are you talking about hanging a 400W HPS over your tank? Don't do that. Please.
im planning on making a diy wooden hood
Sploke
03-29-2008, 1:13 PM
If you're building a wood canopy, look at the kits from www.ahsupply.com. I've used several of them, they are great packages. A 2x65w kit would be a good place to start, I have that over a 55 and can grow most low to med light plants with no co2 or ferts.
jmhart
03-29-2008, 1:26 PM
When it comes to plants, the temperature rating of the bulb is more important. 2500k won't do much of anything for the plants, no matter how many watts you have. On the other side, you have have as little ad 0.5 wpg, and as long as it's 5500k or above, you'll see growth, albeit slow at that low wpg.
Additionally, you may want to try a few more watts over that 55g. This is an interesting article, analyzing Amano's light levels:
http://www.fitchfamily.com/lighting.html
StereoKills
03-29-2008, 1:52 PM
That's a great link jmhart! Interesting to see how his lower volume tanks tend to get much more light compared to the larger tanks. Personally I prefer 6500K or a mix of 6500K and a bulb closer to 10000K.
jmhart
03-29-2008, 1:53 PM
I just picked up some 8800k bulbs from a friend, excited to see how they look.
crazycanuck
03-29-2008, 1:59 PM
so ill shoot for 150 watts.. and 6,700 k any suggestions on bulbs?? ( cfl )
jmhart
03-29-2008, 2:03 PM
Oh, they are cfl's? That changes things. At least 15% of your light will be lost to restrike. If you don't have a good reflector, factor in another 5%. So, 80% of your light is lost. Over a 55g, you need 180 watts.
You can buy a 2 pack of GE 26w "Daylight" 6500k CFL's at Walmart for $7.
StereoKills
03-29-2008, 4:19 PM
I don't know if you'll be able to find much in the way of different Kelvin ratings for cfls. I only had the options of regular cfls and daylight balanced. I of course went with daylight balanced.
jmhart
03-29-2008, 9:13 PM
From my research, I know of two kinds of cfl "Daylight" bulbs. At Home Depot they sell "Daylight" bulbs in either a 2 or 3 pack. They offer wattages up to 25 watts per bulb, and the kelvin rating is 5500k. I do not know the brand.
At Wal-Mart, they have GE 6500k "Daylight" bulbs in wattages from 10 watts to 26 watts. They sell them in two packs.
Screw-in CFL's are not made in higher wattage than 6500k at this time. I don't know about anybody else, but GE has no plans to make them anytime in the future.