# How long should light be on?



## DaveK (Jul 10, 2010)

Every tank is a bit different, and what would be perfect for one system might create an algae farm on another.

I'd start the lighting at about 10 hours a day and then adjust that period up or down as needed.


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## BBradbury (Nov 8, 2010)

*Tank Lighting*

Hello lae...

Aquatic plants are tropical and used to long hours of daylight. I have my tank lights on a timer set for 12 hours on and 12 off. 10 to 14 hours daily is the norm. Keep the food to a minimum and float some Anacharis stems in the tank to keep algae under control. Flush a lot of new, treated tap water through the tank every week to maintain a healthy water chemistry and you'll have few, if any tank problems.

Have fun!

B


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## Kathyy (Feb 22, 2010)

Easy! Increase the bright light by 15-30 minutes every couple weeks as you note that plants are responding well and algae isn't a nuisance.

I doubt you will want the lighting to be at 100% for 12 hours. I found with metal halide that a lot of stem plants closed the tops at 8 hours. Suspect that the day those plants prefer varies depending on the light used. 

You are going to want more nitrogen and phosphorus to help the plants grow. Bright light+CO2+NPKM is much more likely to produce a nice clean tank with healthy plants than one with bright light+CO2+KM alone. Flourish is great stuff for low tech tanks, yours isn't low tech!


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## Raymond S. (Dec 29, 2012)

Plants need sleep also. Allowing those blue lights to be on while you might still view the
tank is fine, but later in the night it would do the plants a favor to have them off for
at least 8 hrs.
Since they have more windows than you might regularly have in a room, the tank I have
in the bedroom gets more ambient light from them than most might get.
I can watch the tank without the light on(before it comes on) in the A.M. and on a
couple of occasions I've had the lights on at 2 or 4 in the morning for some reason
and at that time the plant leaves are closed/folded up towards the top of the plant.
But in the A.M. when I just happen to be up before the light comes on and watch
the tank for a few those leaves are open because of the ambient light coming from
the windows. And the fish don't freak when the tank light comes on because they
already had some light in there.


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## Hoppy (Dec 24, 2005)

Kathyy said:


> Easy! Increase the bright light by 15-30 minutes every couple weeks as you note that plants are responding well and algae isn't a nuisance.


That is a good way to evaluate almost any tank parameter, from CO2 to fertilizer components, to light. All of us obviously enjoy looking at our planted tanks, so we shouldn't mind looking at them critically, too. Watch each type of plant so you are very familiar with how they grow, how fast, what shape leaves, etc. Then when you want to test a change, you have a baseline for determining how the plant changes as a result of what you changed. As long as your change results in positive changes for the plants you can make a little bigger change and watch to see if the positive changes continue. When they don't, you have reached, and passed, the optimum setting for that parameter.

Personally, I'm a bit too lazy to do this, but I admire those who aren't.:icon_smil


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## Jcstank (Jan 3, 2015)

The planted tank is a very complex mini Eco system that involves intervention from you in order to keep things balanced. The health and success of your plants without having algae take over depends on a large number of things like balanced nutrients in the soil and water column, water parameters, available C02, temperature, livestock, frequency of water changes, water flow in tank, overall plant mass in tank, and of course the quality and amount of light (PAR) in a 24 hour cycle. 

The light drives the plants and the nutrients available allow the plants to use the available light to its fullest extent. You have to also take into account the available indirect light in the room like sunlight from windows (indirect or direct) and light fixtures in the room. If you are missing any one critical component than you are likely to have an algae problem. 

My tank does get some indirect sunlight and I tend to keep the on time of my LED light to just 8 hours a day starting from 12:00 PM till 8:00 AM. My tank gets some amount of indirect light from sunrise to 12:00 PM. I suggest that if you are not as experienced with planted tanks that you not allow any more than 10 hours per day and as someone suggested do not run the moon lights all night. The fish also need a period of complete darkness just as they would have in the wild because in the wild the real moonlight is much different.


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## harley (Jul 24, 2015)

Thanks for all the replies! I will start turning off the lights completely when I go to bed. I had a brown algae problem a few weeks ago that's under control now and since that's taken care of I wanted to move onto learning how to keep everything growing and happy. 

I forgot to add that I added API Root Tabs for the first time about a week ago. Is that plus the Flourish once a week ok or should I switch from the Flourish to something else? Thanks, you all are so helpful!


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## keymastr (May 25, 2015)

Flourish is only micro nutrients. With your light and co2 you really need to dose macro nutrients as well. Get some dry fertilizers, they are very easy and much cheaper than buying bottled fertilizers. You would spend around $50.00 on the full line of Seachem ferts and they would only last you a month or so but for about $30.00 you can get a years supply of dry ferts shipped to your door.


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## Doppelgaenger (Jul 20, 2015)

Keymastr is right.

I got a whole pound of KNO3 and KH2PO4, each (potassium nitrate and monopotassium phosphate) for $10.00 total at my local hydroponics shop. the difference between before and after dosing dry ferts is really remarkable. 

Be careful of dosing excel or any other glutaraldehyde based carbon source because some plants won't tolerate it. I have Monosolenium tenerum and it melts when I use liquid carbon.


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## Raymond S. (Dec 29, 2012)

http://www.plantedtank.net/forums/showthread.php?t=922281
To make things easy for someone just starting this you might scrole down to where it says "DIY EI liquid ferts".
I think that would be a good choice for you. After you get aquainted/w ferts better you likely will want to add more of this or that to it. But this works well with most plants
that you would likely have so no real need for that anyway.


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