t8 vs t12
- Thread starter anonymousadrian
- Start date
There is a ton of info in the past about lighting... most of it is in the planted forum section seing how thats where it is most critical. Here are some info:
The smaller the diameter of the bulb (flourescent) the more effecient it is typically. A CF bulb is far more efficient at producing light per wattage of power consumption versus a T12. The main reason is because the bulb is smaller in diameter. The main reason this is the case is because the smaller bulb can excite and heat the gas inside more easily. The larger 1.5" diameter T12 bulb cannot heat the gas up like a much smaller T5/CF bulb. I have used T12, T10, and T8 bulbs on my own tanks. T8,10,12 bulbs all fit the same endcaps (the pin connections are the same) but the ballasts are different. The T8 bulbs use instant start ballasts (generaly on the ballast part number will be an 'IS'). I have succesfully used all the bulbs with electronic T8 IS ballasts without any problems yet. I just completed my new hood wich uses 4 endcaps from my gutted out $6 wall mart flourescent fixtures, and ballasts I got on ebay, overdriven 2X (where a 4 bulb ballast pumps its power into just 2 bulbs - called ODNO for those who havent heard about it).
As far as efficiency goes you can also see that a 48" T12 bulb draws 40W of power, while a 48" T8 bulb draws only 32W. There was some posts that listed the efficiency, i dont have em handy but it goes directly with bulb size, T12, T10, T8, and finally T5&CF. They also now have T6 bulbs which are CF/T5 bulbs with the standard T8,10,12 pin connection so you can get CF/T5 efficiency in a canopy designed for T8 or larger bulbs.
As far as the color, I havent yet seen any official scientific results saying specific wavelengths are the best. It is generally accepted that 5000K-6500K is a good range for plants. It has also been mentioned that plants are pretty adaptable as long as the light isnt excessivly shifted to one particular color.
The best bang for the buck I have found with bulbs are Phillips Daylight Delux found at your local Home Depot for 2 bulbs for $7. They are T8's, 6200K or 6500K cant remember for sure, and are much brighter than the T12's I had. Especially overdriven 2x they are much brighter. I have some photos I can upload of the difference between the bulbs, but I am at work right now.
Also in any hood that has any kind of reflector or even a white backing, the smaller bulbs will have less 'restrike' and allow more reflected light to get back into the tank.
The smaller the diameter of the bulb (flourescent) the more effecient it is typically. A CF bulb is far more efficient at producing light per wattage of power consumption versus a T12. The main reason is because the bulb is smaller in diameter. The main reason this is the case is because the smaller bulb can excite and heat the gas inside more easily. The larger 1.5" diameter T12 bulb cannot heat the gas up like a much smaller T5/CF bulb. I have used T12, T10, and T8 bulbs on my own tanks. T8,10,12 bulbs all fit the same endcaps (the pin connections are the same) but the ballasts are different. The T8 bulbs use instant start ballasts (generaly on the ballast part number will be an 'IS'). I have succesfully used all the bulbs with electronic T8 IS ballasts without any problems yet. I just completed my new hood wich uses 4 endcaps from my gutted out $6 wall mart flourescent fixtures, and ballasts I got on ebay, overdriven 2X (where a 4 bulb ballast pumps its power into just 2 bulbs - called ODNO for those who havent heard about it).
As far as efficiency goes you can also see that a 48" T12 bulb draws 40W of power, while a 48" T8 bulb draws only 32W. There was some posts that listed the efficiency, i dont have em handy but it goes directly with bulb size, T12, T10, T8, and finally T5&CF. They also now have T6 bulbs which are CF/T5 bulbs with the standard T8,10,12 pin connection so you can get CF/T5 efficiency in a canopy designed for T8 or larger bulbs.
As far as the color, I havent yet seen any official scientific results saying specific wavelengths are the best. It is generally accepted that 5000K-6500K is a good range for plants. It has also been mentioned that plants are pretty adaptable as long as the light isnt excessivly shifted to one particular color.
The best bang for the buck I have found with bulbs are Phillips Daylight Delux found at your local Home Depot for 2 bulbs for $7. They are T8's, 6200K or 6500K cant remember for sure, and are much brighter than the T12's I had. Especially overdriven 2x they are much brighter. I have some photos I can upload of the difference between the bulbs, but I am at work right now.
Also in any hood that has any kind of reflector or even a white backing, the smaller bulbs will have less 'restrike' and allow more reflected light to get back into the tank.
tai95 said:
you have to subtract the 18" overhang. its a 30" tank and 48" lights. 18" worth of light doesn't count. i even tried blocking off the sides of the tank so that light couldn't get in from the sides and it was still SO BRIGHT. its only 50 watts over the 20g.
Well I went ahead and dug up some pics I took of various bulbs FWIW.
From left to right:
Flora-Glo T10 40W, GE Plant & Aquarium T12 40W, Philips Daylight Deluxe T8 32W, and Power-Glo T10 40W
To prevent the lights from washing out the picture and all being about the same I used a shutter speed of 1/400 sec anf aperture of 5.6. This also reveals deeper coloring that what it would look like in person, i.e. the flora glo isnt really that pink and the power-glo isnt really that blue. You can see the T8 daylight bulbs really kicks the others @$$ hands down. And its the least expensive of all them, and draws less power. The T12 aquarium bulb is so dim in comparison that it doesnt even appear to be on in the picture. Remember though that these are all different bulbs, its not 100% apples to apples. For example even in the same size and power rating a daylight bulb will look different than a economy commercial bulb, or a cool white bulb, etc. Also FWIW I have yet to find a 4 foot T12 bulb that is as bright as an equivelent T8.
From left to right:
Flora-Glo T10 40W, GE Plant & Aquarium T12 40W, Philips Daylight Deluxe T8 32W, and Power-Glo T10 40W
To prevent the lights from washing out the picture and all being about the same I used a shutter speed of 1/400 sec anf aperture of 5.6. This also reveals deeper coloring that what it would look like in person, i.e. the flora glo isnt really that pink and the power-glo isnt really that blue. You can see the T8 daylight bulbs really kicks the others @$$ hands down. And its the least expensive of all them, and draws less power. The T12 aquarium bulb is so dim in comparison that it doesnt even appear to be on in the picture. Remember though that these are all different bulbs, its not 100% apples to apples. For example even in the same size and power rating a daylight bulb will look different than a economy commercial bulb, or a cool white bulb, etc. Also FWIW I have yet to find a 4 foot T12 bulb that is as bright as an equivelent T8.
T12s and t10s are generally used with a magnetic rapid-start ballast. T-8 are used with electronic, instant start ballasts; in commercial fixtures, anyway. T8 are more efficient since, as was pointed out earlier, a 48" t12 is 40 watts and a 48" t8 is 32 watts, yet it delivers more lumens than the 40 watt lamp. T8s use less power and give more light.
Mark
Mark
