# Question About Lighting



## captroper (Mar 19, 2012)

Hey Guys,

I have a 20 Gallon Freshwater tank set up with fake plants and rocks and (now) exclusively guppies. I've had this tank set up consistently for the past 3 years and have not introduced any new fish to it. 

Over that time I have kept the tank light on 24/7. I now heard that this is bad for the fish as they're actually supposed to receive darkness. My first question is, is that accurate? If so, should I start turning the light off at night? My concern is that they've gotten used to having it on at all times now, so turning it off may stress them. 

Thoughts? 

Thanks, 

Adam


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## hanky (Jan 18, 2012)

WELCOME
Wow you've had your tank lights on for 3 years? 
Turn them off at night so the fish can rest. 10 hours of light a day is fine. Do you have any algae problems?


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## BBradbury (Apr 22, 2011)

captroper said:


> Hey Guys,
> 
> I have a 20 Gallon Freshwater tank set up with fake plants and rocks and (now) exclusively guppies. I've had this tank set up consistently for the past 3 years and have not introduced any new fish to it.
> 
> ...


Hello Adam...

Most aquarium fish are tropical, so need no more than 12 hours of daylight and do need a period of dusk or darkness. I have my tank lights on timers set for 12 hours on and 12 off.

Too much light can have a negative affect on the reproduction cycle of tropical fish.

If you like, you can leave a small night light on the room to mimic dusk, so your fish can get used to a little less light. It might be helpful.

B


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## captroper (Mar 19, 2012)

@Hanky

Thank you very much, Yep, I sure have. Yeah, I get pretty rampant algae growth, I have to scrub it off every time I clean out the tank. Though, I recently purchased a few ghost shrimp and apparently they included a snail because there are about 15 snails in there at the moment. 

@BBradbury

Thanks, I'll definitely do that!


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## hanky (Jan 18, 2012)

all that light is causing your algae issues go down to 12 hours and see how that works, or 10 if your still getting algae, although the snails will help alot too.


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## TimKessler (Mar 20, 2012)

You definitely need to give your guppies some darkness. Too much light will place too much stress on them which will affect their health and reproduction. And that's also the reason for your algae growth. This goes for any other fish too, not just guppies.

Tim


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## jamesk (Mar 24, 2012)

Turn it off when you go to bed. Fish need rest too.


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## jrman83 (Jul 9, 2010)

Forget the fish, fight the algae. just kidding....can't imagine how much algae must grow. My tank lights are rarely on when I'm either not up or not home. My timers are set to me....makes it easy.


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