# Lights should be on for 10-12 hours daily?



## jrtiberius (Dec 1, 2005)

I keep reading...
"Lights should be on for 10-12 hours daily"
Why? Why not leave them on 24/7? From my understanding plants do not need a light/dark cycle unless your trying to force flowering, and the plant will photosynthesis constantly and grow faster than it would if you had a dark period.


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## trenac (Jul 16, 2004)

Plants in nature have a light/dark cycle, this is what we are trying to duplicate in our aquariums. All that our plants need to photosynsize properly is 10-12 hours daily, anything beyond this is excessive and more or less useless to the plants. However algae will get a good foot hold when you have the lights on for longer periods time.


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## DonaldmBoyer (Aug 18, 2005)

All plants need a dark period. It is when they respire, and it is crucial for their health! Otherwise, they will eventually die.


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## RTR (Oct 28, 2005)

I don't use such in my tanks with fish, but my 24/7 lighted veggie filters are doing just fine. I question the dark period requirement as being valid and absolute. 

But I don't want my dispay tanks on 24/7, no thanks.


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## DonaldmBoyer (Aug 18, 2005)

Take it from someone who studied plant bio/phisiology in college: if you are growing plants that you want to look healthy, you need to allow for a dark period of at least 8-10 hours for photorespiration.


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## Robert Hudson (Feb 5, 2004)

Several years back I went on vacation and got somebody to care for my 20 gal tank while I was gone. It was full of aponogeton bulbs with about 2" growth on them. Well this person decided to plug the lights in so they would be on 24/7. Three weeks later when I returned, I had a jungle tank with 2 foot long leaves on each bulb. I shut the lights off at night and within a week all the plants were dead. They burned themselves out and the sudden lack of light shocked them. To go thru proper photosynthesis, plants need a complete night and day cycle


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## houseofcards (Feb 16, 2005)

I completely agree with lights off, but I do have a related issue to discuss. At night if the lights on the aquarium are off, but there is a light left on in the room, does tha effect the ability for the plants to respire. I'm talking about a room light left on about 5 feet away.


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## kennyman (Oct 19, 2005)

I am not sure but respiration may not actually stop during the light portion of photoperiods.


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## DonaldmBoyer (Aug 18, 2005)

Naw...a lamplight isn't going to be strong enough to affect the growth of plants in an aquarium....it should be fine!

Kennyman....respiration totally stops when the lights are on. Plants produce oxygen during that time instead of using it.


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## RTR (Oct 28, 2005)

LOL! I do remember RPH's incident of the 24/7 lighting, and I must admit that it started me on a series of aquatic trials that are still ongoing. I do believe fully that his report of the incident is fully accurate. My question then was: what if he had maintained the light and kept the nutrients up? I do not believe that the plants would have faced obligate collapse and death. I have operated 24/7 lighting for a number of plants (terrestrial and aquatic)l and to date have not lost any of them. Some plants do show some growth differences, but I no longer consider total metabolic failure as a given at all.


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