Light bulb question

[Boogety48]

I won a tank at an auction and need to replace the bulb in the hood. It has a T20 bulb in it. Can I put a T8 or lower in it? I don't know anything about fluorescent light bulbs other than the T is how big around it is. The thing that concerns me is the T20 looks way to big around to have been in the hood. I don't want to mess something up by not putting in the right bulb. Someone please help I want a light on my tank without having to buy a new one.

 

[Boogety48]

Can anyone help? I want to get a light tomorrow but I don't want to buy the wrong thing.

 

[jmay33]

You should take the hood in with you. There's no harm in it.

 

[blert]

Are not T20s just capped screw in CFL bulb? Search them, that's all I come up with. If so, you can put in any screw in CFL bulb you like as long as you do not exceed the rated wattage of the fixture.

 

[phin]

I don't know about T20, but if you are changing from T12 to T5 you need to change the endcaps so the pins in the new bulb will fit. If your are changing from a T20 (2.5" diameter bulb) to a smaller bulb you need to make sure the pins will fit in the endcaps.

 

[blert]

T12, T10 and T8 are pretty much interchangeable. The smaller bulbs will be driven harder though. T5 would need different end caps and drivers.

 

[tonedogz]

I don't think the ballasts are the same for different size bulbs. They might burn out the bulbs if there to big an output or would't power them if there to small.

 

[blert]

I don't think the ballasts are the same for different size bulbs. They might burn out the bulbs if there to big an output or would't power them if there to small.

There not, but you can run a T8 (or T10) with a T12 ballast. The bulb will be "overdriven" and it will shorten its life but it will work. I run a 32watt T8 bulb in an old fixture originally designed for a 40watt T12.

 

[Boogety48]

I tried doing a T8 bulb but it just flickered on and off. I think the hood is bad, but its nice to learn off this. Like I said I don't know anything about fluorescent bulbs. The ends fit in but like I said it just flickered.

 

[blert]

How many watts is the fixture and what length bulb?
How old is the fixture?
If it is old, have you tried replacing the capacitor (the round white/silver thing on the underside that just twists and pops out)?

 

[Boogety48]

I'll have to look at the watts, I just tried a standard aquarium bulb. Its a 24" bulb. I don't know how old it is. I got it at an auction. It looks pretty old and the part inside where the bulb is, is drying out and chipping apart. I may try to change the fuse tomorrow before I buy a new strip.

 

[Boogety48]

I ended up just buying a new strip light. The wattage on the old light was 15. I changed the fuse but it still just flickered.

 

[REDCHEVYBLAZER]

Not to hijack a thread, but if you wanna pm me the answer to not hijack it, that'd be great, but my tank came with 20 watt bulbs. My replacement is a 15. WIll having a 20 and 15 matter at all?