# Advantages of sunrise/sunset simulation



## TomTo (Mar 1, 2016)

Hi!

Is there any advantage to sunrise/sunset simulation for the plants? Or is it more of an aesthetic thing for the viewers?

I was thinking that it might simulate real life and as such some processes in the plants may perform better. Anyone with knowledge on this?

Furthermore, how should CO2 be simulated then?


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## Hoppy (Dec 24, 2005)

Simulated sunrise/sunset is done for the enjoyment of the viewers of the tank, and, to a very limited extent, for the fish. Plants don't need that. If you read the descriptions of the award winning aquascapes you won't find many, if any of them that used programmed sunrise/sunset lighting. And their plants do pretty well.

CO2 is needed when the light intensity is above about 35 PAR. Lower than that and the plants grow so slowly they need little carbon.


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## Kathyy (Feb 22, 2010)

I use a graduated light cycle for my enjoyment. I can have the lights on for much longer and see into the tank any time I am in the room. With a 6' tank that is a big deal. 

I turn on the CO2 when lights go on. It isn't necessary but any CO2 helps the plants to a degree. It goes off once estimated PAR is at about 35 though as plenty stays in the water until PAR is really low.


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## Seetide (Feb 25, 2016)

Just because award winning aquascapes don't use it, doesn't mean it may not be beneficial to plants. Obviously it is not necessary at all, but a great question. This is how plants in the wild receive their light everyday. It would be interesting to set up two identical tanks, with the same plants divided from bunches and note any differences over time.


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## aja31 (May 25, 2013)

There may be a minimal advantage, but not a needed one. We can already grow plants fast enough that they need to be trimmed 1-2 times a week. If you want plants to grow faster or bushier, then use one of the established methods for doing so (PAR, ferts, CO2). The gain in growth and health by modifying these appropriately will FAR outweigh any advantage in sunrise/sunset cycles. 

It does however offer a fairly tangible benefit for the fish, who undergo a fair bit of stress by bright lights suddenly turning on. Imagine if you were woken up every day by someone shining a cars headlights directly in your face every morning. 

Finally it allows you to see your scape and fish for many more hours in a given day. You can have visible light for viewing, with 0 PAR, for 20+ hours a day as opposed to 6-10 hours of high PAR light that is usually the limit.


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## 691175002 (Apr 28, 2009)

Its possible that short bursts of high intensity might keep the plants low and dense at slower growth rates, but without testing its hard to know. 

I like having long fades because it lets you have a very long viewing period. I do 3 hours ramp on, 6 hours of 100%, and 3 hours ramp down.


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## LS6 Tommy (May 13, 2006)

All I know is if my lights aren't staged a little and come on instantly to full brightness, my fish get spooked and dash around the tank. 5+ inch Discus can get hurt that way...

Tommy


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## crazyplantguy (Mar 21, 2016)

I wish i had that option. Plants don't care. But my angels freak out when I kick the lights on. My largest hangs out right under them in the morning. so I can only imagine getting blasted in the face with light all the sudden. Lol.

Sent from my SM-G920P using Tapatalk


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## talontsiawd (Oct 19, 2008)

It can prevent fish getting spooked as someone said. I had a way overkill setup, 4x24 watt T5HO setup and even with two bulbs going on and another two later, it spooked my fish. I experimented with going really overboard, but with a super short photoperiod and noticed more fish jumped. I never had this issue with a low to moderate light setup, even reasonable high light, I doubt it would be super problematic, all my high light tanks were staged (this was pre LED at least off the shelf) so not using a dimmer but bulbs came on over a period of time and went off the same way.

In general, I would consider it more of a viewer thing, not for the fish.


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