Do the fish get agitated if you turn the light out quickly?

[Temp]

Here's a scenario:

You have a lamp nearby, with a few healthy fish. It doesn't matter what fish you have in your tank, just enough for you to spot any unusual behavior of each fish. The lamp is turned on, and was allowed to stay on until it's night. Finally, it's nighttime, and you are to turn it off.

1. Should you slowly fade the light from 100% bright, to 0%, as in moving a book and slowly cover the light, mimicking the sunset, and then turn the light off once it's completely pitch black?

2. Or should you just turn the light off quickly, and shrug to yourself saying, "Don't worry, it's harmless."?

3. Or, just turn the lights on and off using a special jumper, so that the light, at first, is bright, then slowly, the light is going on/off pretty fast, then slower, slower, slower, until the light's going on/off per second, then turn the light off completely?

Note: The jumper is used to make the frequency of the electricity going through the light bulb slow down to a halt, so that a perfectly normal light bulb would then seem like the light's going on/off continuously.

 

[meegosh]

I have all my tanks on a timer so it is on or off. No dimming or anything like that. If anything I think it is worse when the lights come on, 96watts over 30g is bright!

 

[taylorodw]

I agree with meegosh. Fish may show a little distress because their eyes are adjusting and they can't see - so they feel vulnerable to any threats. However, once their eyes adjust it's all gravy baby

The only thing is, I would not feed immediately when turning the lights on or off - the fish may not be able to see the food!

 

[adeebm]

My fish don't mind me turning lights on/off. They get used to it. Infact my betta knows its feeding time when the light goes on

--Adeeb

 

[BigJim]

My lights also go off with a timer. I'm planning to try a dimming fixture in the future, but mostly because a natural light cycle with the moon phases can induce spawning and other interesting behaviors. The fish don't really stress with the sudden on and off.

 

[meegosh]

I'm planning to try a dimming fixture in the future, but mostly because a natural light cycle with the moon phases can induce spawning and other interesting behaviors.

You planning on using LEDs? Not sure how you would accomplish dimming with cf or mh lights.

 

[BigJim]

You planning on using LEDs? Not sure how you would accomplish dimming with cf or mh lights.

There are dimmable CFLs, but I am planning to give LEDs a shot. I need to learn more about microcontrollers first.

 

[DragonFish71]

Our moon lights come on about 15 minutes before our main lights go off. Never seen the fish tweak from that. Although our male firemouth tweaks just because

 

[Mark Hewitt]

I've never noticed any fish freaking out when the light goes off. Certainly do when the lights go on! Despite only having 2 x 5W bulbs in there they are noticeably more subdued and less active when the lights are on.

 

[logansmomma1228]

My fish love when the lights come on, because they know I am there! Lol. They come and hang out with me at the glass (mr. betta and the dwarf puffers) The ones in the 29 just go all over lol

 

[dkpate]

I always turn a room light on before I turn the tank lights on. I also turn a room light on when I turn the lights off at night, and since I stay up late, I cover my tanks with towels.

 

[AdamHorton]

There are dimmable CFLs, but I am planning to give LEDs a shot. I need to learn more about microcontrollers first.

I know a thing or two about microcontrollers -- an easy way to dim an LED is just to oscillate it on and off. You may not need a microcontroller to do that depending on your setup

 

[krap101]

I'm wondering... we see in 30hz or so and 60hzish in the periphery, but I wonder at what rate fish see?

 

[BigJim]

I know a thing or two about microcontrollers -- an easy way to dim an LED is just to oscillate it on and off. You may not need a microcontroller to do that depending on your setup

I'm planning to run some high-power LEDs using the PWM functions of the microcontroller. The project just got bumped to the back burner for a while. My wife and I bought a house two months ago and it needs work, so my spare time evaporated. It might just have to wait for winter.

 

[AdamHorton]

If you're going to use a microcontroller, then PWM is definitely the way to go. I just thought you might be able to buy an oscillator to do the same thing for less, but maybe not. It depends on your setup.