I've got a 29 gallon tank and a reptile dome over top. the tank is heavily planted. And i currently have a 26watt=100watt cfl over top in the dome. Some people say that its fine and they are getting 100watts. Others argue they are only getting the 26 watts. tell me which is which. if they are only getting 26 watts then can u give me a bulb name that will fit the fixure (regular light bulbs fit) and will be 100 watts total. I looked at lows and there were 6,500k bulbs BUT they were all compact florecents. and the other ones that werent didnt list the kelvins. So i need a bulb that'll be 100watts on the plants and is 6000-7000k.
29 gallon light bulb
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a 26w bulb is equivlent to 100W.
you are getting the same light you would if you had a 100 incandescent bulb on the tank.
CF bulbs emit 4x as many lumens per watt as compared to incandesent bulbs, hence the higher light output with the lower wattage.
26w is not 26w in this case.
26w gives you 100w worth of light because the lumen output per watt is much higher.
most of the energy used to light an incandescent bulb is wasted as heat.
not the case with a CF bulb, hence the lower wattage while still producing the same amount of visible light.
you are getting the same light you would if you had a 100 incandescent bulb on the tank.
CF bulbs emit 4x as many lumens per watt as compared to incandesent bulbs, hence the higher light output with the lower wattage.
26w is not 26w in this case.
26w gives you 100w worth of light because the lumen output per watt is much higher.
most of the energy used to light an incandescent bulb is wasted as heat.
not the case with a CF bulb, hence the lower wattage while still producing the same amount of visible light.
depends. one issue you may have is that one bulb will act like a point source of light.
in other words, the light will not be spread out over the area of the tank, but concentrated locally close to the bulb.
so the plants directly under the bulb would probably do okay. but those far from it may not. you might be better to look at other lighting options.
perhaps another member can suggest one of the coralife fixtures with the legs that would fit over top of your screened in top. this would probably be much better for plants. also the colour temperature would be better for growing plants also.
in other words, the light will not be spread out over the area of the tank, but concentrated locally close to the bulb.
so the plants directly under the bulb would probably do okay. but those far from it may not. you might be better to look at other lighting options.
perhaps another member can suggest one of the coralife fixtures with the legs that would fit over top of your screened in top. this would probably be much better for plants. also the colour temperature would be better for growing plants also.
12 Volt Man;3581000; said:
See, this is the kind of thing that confuses/misleads people. 26W is 26W, watts don't measure light.
This would be a lot easier if people stopped even mentioning incandescent bulbs with regards to aquariums because they don't matter.
exactly my point.
a 26w CF bulb emits more light than a 26w incandescent bulb.
it emits an equivlent of 100w of light.
the plants don't care how many watts the bulb is. only how much light that is emitted.
thus, people saying that 26w is 26w is wrong as far as how well the plants will do.
the plants don't care how many watts the bulb is. they only care about how much light is produced from the bulb.
which is, in this case, equivent to the same output that a 100w incandescent bulb would emit...
but, as I said, it doesn't mean there are not better lighting setups.
a 26w CF bulb emits more light than a 26w incandescent bulb.
it emits an equivlent of 100w of light.
the plants don't care how many watts the bulb is. only how much light that is emitted.
thus, people saying that 26w is 26w is wrong as far as how well the plants will do.
the plants don't care how many watts the bulb is. they only care about how much light is produced from the bulb.
which is, in this case, equivent to the same output that a 100w incandescent bulb would emit...
but, as I said, it doesn't mean there are not better lighting setups.
When you're trying to figure out how much light you need, ignore the incandescent equivalence. If you're basing your light requirements on the WPG rule, the actual wattage of the bulb is what matters (assuming you're using CFL or other efficient lighting types).
That said, the WPG rule kind of sucks. Even among common aquarium lighting, efficiency varies a lot. CFL bulbs are okay for smaller tanks, but they aren't as efficient as T5 or power compact lighting. I've got a 2x24W T5HO fixture on my 29G, it produces much more light (or at least directs more into the aquarium, which is what matters) than two 26W CFLs.
I meant that a 26W bulb is 26W. Saying it is 100W is misleading unless you specify that you are comparing it to a 100W incandescent bulb.
The light produced by a 26W CFL bulb is approximately equal to a 100 watt incandescent bulb.
That said, the WPG rule kind of sucks. Even among common aquarium lighting, efficiency varies a lot. CFL bulbs are okay for smaller tanks, but they aren't as efficient as T5 or power compact lighting. I've got a 2x24W T5HO fixture on my 29G, it produces much more light (or at least directs more into the aquarium, which is what matters) than two 26W CFLs.
12 Volt Man;3583656; said:
I meant that a 26W bulb is 26W. Saying it is 100W is misleading unless you specify that you are comparing it to a 100W incandescent bulb.
The light produced by a 26W CFL bulb is approximately equal to a 100 watt incandescent bulb.