# Lighting question :(



## daniel89 (Nov 28, 2009)

My lights in my 55 gallon tank are regular 18" bulbs, and I want to replace them as I'm buying a few plants for my tank and I was wondering if T8 day light 15w 6500k bulbs would work? These bulbs are made by GE and are day light bulbs. Just trying to cut a few corners on some expensive light set for a few plants


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## bmlbytes (Aug 1, 2009)

Is your fixture a T8 fixture? 2 15w bulbs might be kind of low light, but you could grow some low light plants in it.


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## daniel89 (Nov 28, 2009)

No it's not a t8 fixture there just bulbs that are in walmart in the lighting section in hardware and I see them and figured I'd ask. What's the worst that could happen if i were to put them into my regular fixture cause I have regular bulbs that are 15w that are running in it right Now.


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## emc7 (Jul 23, 2005)

What size and Wattages are the current bulbs? T12, T8, T5 are all bulb sizes (fatness). Pin sizes are the same for T12 & T8. The skinnier T8 fit in T12 sockets. but "Running a T8 tube with a ballast for T12 will reduce lamp life and can increase energy consumption" (wikipedia). 

If the length, size, and Watts match, choose any wavelength you like, they should work just fine. I do buy GE daylight bulbs @ lowes when I need one quick and they are nice and white and bright. 

There is some wiggle room. Ballasts & starters often will light bulbs with a range of wattages. If you have a starter, pull it out and read it. But be careful changing wattages and sizes. 

What can go wrong:

Bulb has higher wattage than fixture usually just doesn't light all the way and you have to go back and buy the right bulb.

Bulb is too fat (T12 in T8 fixture):, bulb get stuck, hot bulb melts or yellows plastic that skinnier bulb wouldn't touch. 

Worst possible outcomes: bulb, starter, ballast, switch, and/or whole fixture get destroyed and need replacement, light sets your house on fire. 

It is possible to replace assorted pieces of these lights, even change them form one type of bulb to another. Lowes sporadically has all the parts you need. 

"regular" doesn't tell me what you have. T12 are, I think, 1.5" inches in diameter, T8 are 1". old-style T12 ballasts are getting phased out and finding replacement ballasts (08-2010) and eventually bulbs is going to get difficult. If you get a new light, even a shop-light, avoid T12. 

2 18", 15W bulbs on a 55 is low light. Use only low-light plants and expect them to grow slowly. Retrofit kits to double bulbs are are out there but aren't real cheap. I have on occasion just added another strip light (ugly).


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## daniel89 (Nov 28, 2009)

Thanks for the good info I'm guessing my regular light fixture is a t8 model cause the bulbs are the same size and everything. I do have a power compact light fixture but it won't fix my 55 tank with my hoods :/ and even then The moon light is missing the night light is blown and the day light works so yeah :/


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## jones57742 (Sep 8, 2007)

daniel89 said:


> No it's not a t8 fixture there just bulbs that are in walmart in the lighting section in hardware and I see them and figured I'd ask. What's the worst that could happen if i were to put them into my regular fixture cause I have regular bulbs that are 15w that are running in it right Now.


They are probably T5 bulbs. Verify before purchasing.

The two 15's would be considered very, very low lighting.

IMHO you will be happier with 10000K bulbs due to the yellowish tint emitted by the "daylight" bulbs.

The current ballast may not have sufficient power in order to illuminate the new bulbs.

*and everything which em said also!*

TR


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## daniel89 (Nov 28, 2009)

i figured instead of buying the bulbs id just steal them so i did lol anyhows... i put on in and the bulb turns on but the light sorta moves like flickers but stays lit at the same time, its kinda hard to explain. plus it put a green tint in the water with the new bulb. lol

:update - i asked my father about it with the light pulsing and he said its just the gases in the tube heating up cause they are cold. so all is good and it looks alot better with a tad green tint gives it that realistic look :O


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## bmlbytes (Aug 1, 2009)

Although florescent bulbs do need to warm up, that should take a second or two. You probably have the wrong ballast for your bulb.


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## lohachata (Jan 27, 2006)

go to home depot...buy a 4 ft. shoplight..these days they take T8 bulbs.lower wattage but more light..get a couple of daylight bulbs and you are good to go..should give you the light equivilent of about 2 watts per gallon..


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