1,500k/50w for a 20 gal a problem?

[MyShrimpDied]

Hey guys, i was looking for a lighting fixture around my house and i found a hood that will hold screw-in flouro bulbs, my question is, the bulbs that i put in equal 50 watts total but only have a lumen amount of 1,500. Is that a problem, does aquarium lighting NEED to be between 5,000 and 7,000 lumen? and if it doesnt, will those bulbs in my tank be a problem?

~ MyShrimpDied

[Captain Hook]

Lumens and K are not the same thing.

Also when you say equal to 50 watts, is that what the box says? Is it actually a 10 or 15 watt bulb? If so that's the light you have on the tank, I would guess it's 10-20 watts.

[MyShrimpDied]

It says 'energy used' 25 watts. and it says 'light output' 1600 lumen, so what exactly do i have?

~ MyShrimpDied

[phanmc]

When people are tossing around the 5,000 to 6,500k they're not talking about the lumen (total light output) but the color temperature. Does the bulb have anything on color temperature or whether its a "soft light" or "daylight" bulb?

[MyShrimpDied]

No, all i could find were the bulbs, the color of the bulb is yellowish, more like an incandescent bulb.

~ MyShrimpDied

[phanmc]

if its a yellowish color then its a soft light bulb which would be around 2700k. full spectrum bulbs are very white or bluish white.

[happychem]

Just to clarify: Lumen does not refer to "total light output", although it implies that it does. Lumen means the brightness of the bulb to our eyes. Our eyes are more sensitive to greens than blues or reds, photosynthetic requirements are the opposite. Lumen is still a vague indication of brightness, but you can have a plant bulb with very low lumen output, terrible K rating (in the 6500K 'ideal' respect), aweful colour (purpleish), but be exactly what the plant is looking for.

Similarly, a true daylight bulb will have lower lumens than a more green bulb of the same power.

What you've got is a 25W compact fluo. screw in. From your description, it sounds like the 'soft white' variety. Those bulbs always make the point of saying equivalent to X Watts, but it's a marketing thing. What they mean is that it's as bright as an incandecent bulb of that many watts. Otherwise people who've grown accustomed to their 60W bulbs would never buy the "energy saver" rated at 15W, they'd think it too dim. But this has nothing to do with the watts per gallon that is often quoted for aquaria.