30 watt bulb in 25 watt fixture

[UserName336]

I have a 36 inch fluorescent light fixture that i picked up for cheap (i dont have a whole lot of room which is why i opted for the 36 as opposed to the 48 inch) but its rated at 25 watts. i saw that the reptisun bulb was 25 watt (according to ZooMed's website) and i had it ordered in by a local shop since they were sold out. it arrived today but the bulb says it is 30 watts. i didnt notice this until i got home by which time the store was closed.

my questions are:
1. can i still use this bulb in my fixture?

2. are the reptisun 36 inch bulbs 25 watts like the site suggests or are they actually all 30 watts?

3. (sort of off topic but...) can i use lower wattage fluorescent bulbs (say 25 watt) in a higher wattage fixture (30 watt). just want to know for future fixture purchases i make

thanks for your help

 

[Wykd]

Fluorescent lights are classified by type... t12, t5, t8, t5ho, etc....

If the fixture is a t12 then you can not use a t8 light in it. You need to determine if the fixture is the same type as the bulb, that will be what drives if its usable or not and is usually what drives the watts of the bulbs.

 

[UserName336]

yeah, i'm quite aware of this. i know the basics when it comes to lighting just nothing about rated wattages besides the common knowledge of "if its fluorescent lighting, match the wattage". the light and fixture are t8. the light is 30w but fixture is 25w.

 

[Wykd]

when it comes to fluorescent lights i would not exceed the max rating. That can overheat the ballast and possibly cause the bulb to pop. Then you have mercury and glass raining down. That's about as basic as you need to know... don't exceed the rating

 

[UserName336]

okay, thank you. i had a feeling i could blow a bulb by doing it. thats what the home depot guys told me, but the pet shop seems to think that i could use a 40w bulb in a 15w fixture with no issues... they refuse to refund my bulb

 

[UserName336]

just noticed that on the bulb itself (reptisun 5.0) it says f25t8, which if i understand the system correctly it means it is a flourescent(f) 25w(25) (t8) bulb, yet the package claims to be 30w. does anybody know which is actually true?

 

[Calypso]

Blow a bulb, and possibly start a fire.

 

[UserName336]

its this fire thing thats starting to throw me. i used to believe it at first, but the more i look into it, the more i realize that something is wrong there. most balasts take a range of different wattages. the one in one of my fixtures can do two different t12 bulbs, as well as t8 bulbs ranging from (dont quote me on this) 17w to 34w. i just dont see how a bulb that falls within that range, even though it is listed as 30w on the package, shows to be 25w by its markings on the bulb yet never lists the actual wattage on the bulb itself, would cause problems. to me, it seems like this is a mistake, faulty advertising, or the reptile industry trying to make us buy their specific fixtures and overspend on them.

i wired the fixture myself and had the bulb running for several hours before shutting it off. tomorrow will be a 24 hour test. i will continue running it like this (while i'm home) until i'm confident that nothing will happen, however, you can usually tell right away with flourescent bulbs. they either wont start up, or will be dimmer than normal, right? correct me if i'm wrong, but if it just starts up normally, all is good?

 

[Carlton]

its this fire thing thats starting to throw me. i used to believe it at first, but the more i look into it, the more i realize that something is wrong there. most balasts take a range of different wattages. the one in one of my fixtures can do two different t12 bulbs, as well as t8 bulbs ranging from (dont quote me on this) 17w to 34w. i just dont see how a bulb that falls within that range, even though it is listed as 30w on the package, shows to be 25w by its markings on the bulb yet never lists the actual wattage on the bulb itself, would cause problems. to me, it seems like this is a mistake, faulty advertising, or the reptile industry trying to make us buy their specific fixtures and overspend on them.

i wired the fixture myself and had the bulb running for several hours before shutting it off. tomorrow will be a 24 hour test. i will continue running it like this (while i'm home) until i'm confident that nothing will happen, however, you can usually tell right away with flourescent bulbs. they either wont start up, or will be dimmer than normal, right? correct me if i'm wrong, but if it just starts up normally, all is good?

I don't have the technical lighting expertise you do, but I do remember having trouble using ReptiSun bulbs in the cheaper fluorescent fixtures that should supposedly work. The ReptiSuns tended to overheat or shorten the life of the ballasts. I also noticed the slower startups and fluctuating light level. When I switched to aquarium hoods with heavier ballasts they lasted forever.