Dimmers

[freshfishies]

Is it possible to have dimmer switches on flourescents?
My fish seem to scatter and freak out for about 30 seconds after turning the light on or off. I read this is stressful (which I can understand), so does anyone out there have this set up or any suggestions? Thanks

[Soeman]

If you inspect the packaging of any dimmer switches, you will notice that they all indicate that they should not be used with flourescent fixtures. Additionally, only some are rated for use with motors like ceiling fans.

Whether or not they _can_ be used is another matter however. CSA safety regulations require that these warning be printed, but _sometimes_ it is because 1 time in a thousand there will be an electrical problem that may cause a power surge, which 1 time in a million will cause a fire. Personally I'm more likely to cause a fire/flood with all the diy crap i pull :p

But unless you know the reason why dimmers are not rated for use with fluorescent fixtures, I would not risk it.

The most often used method for gradually increasing light for aquariums is to have multiple tubes on different ballasts that are turned on/off sequentially. I think somewhere in the diy/equipment forum there is a post of a guy who built a stand/cover with 6 tubes turning on sequentially (though I might be remembering a post from another forum :s).

[JetJumper]

http://members.misty.com/don/f-dim.html

[Soeman]

I browsed though just quickly. Am I to understand that the only problem with dimming of fluorescent lights is the excessive wear it causes?

I would also note that while I do not have progressive lighting for my tank (as much as I'd like to), the lights _are_ on a timer. I have found that once fish get used to the timing, they exhibit very few signs of stress when the lights come on.

[magnosis]

As far as I know, a fluorescent light cannot be half-on.  It's either full on, or full off.

There are a few companies (Lutron, for instance) that manufacture "fake dimming" ballasts & switch boxes.  What they do is turn off / turn on the bulb something like 60 times per second, such that the bulb always stay in the "warmup" state.  Expect to pay a lot of money for those.

Don't take my word on it.  I remember reading something about it in a Hi-Tech paper last summer but can't remember the exact details.

[freshfishies]

**I would also note that while I do not have progressive lighting for my tank (as much as I'd like to), the lights _are_ on a timer. I have found that once fish get used to the timing, they exhibit very few signs of stress when the lights come on.**

I've actually noticed this recently and am not really worried about them as much.

Great information guys! Thanks:)

[Brent Shaver]

I work with flouresents and dimmers all the time, although not together.  The reason it is not suggested is because when you dim the flouresent you actually over work the balast and can cause a fire.

NOTE:  Should a fire start and they see a dimmer on a flouresent fixture, not only will your insurance abandon you, but the fire marshall will charge you with neglegance.

[new2salt]

Yes, there are dimmable ballast systems available. Both T5 & T8
There is a good post on the planted tank - http://www.plantedtank.net/forums/lighting/84655-dimmable-t5ho-ballast.html

MUST be used with approved controller

If you decide to investigate further or purchase - Find out & make sure these items meet Canadian & Provincial Electrical Codes & Standards.

Should you be so unfortunate as to experience an electrical equipment malfunction which is determined to be the cause of the devastation called a FIRE and you lose anything, your Insurance Co. has a way out and will never pay out your claim.