# 10 hours min photo period???



## tetra73 (Aug 2, 2011)

I was googling on GSA and came up with a thread by Diana. 

"I would consider increasing the light photoperiod from the current 10 hr to at least 12 hr. 

You may think that you're getting good plant growth, but it may be suboptimal for many species in your tank. Suboptimal plant growth translates into algae problems. 

The expert (Christel Kasselmann, _Aquarium Plants_, 2003, p. 52) recommends that the daily lighting period for planted aquariums should be between 12 and 13 hr. A reduction to as low as 10 hr may be handled temporarily by many plants, but her studies showed that several species collapsed entirely after several weeks.

http://www.aquaticplantcentral.com/forumapc/el-natural/62400-green-spot-algae-2.html

I use a 14+ hr daylength for all tanks with a 4 hr afternoon siesta. Lights are on only 10 hr but the daylength works out to 14 hr.

One should never ignore the minimal lighting requirements of aquatic plants to [Ebay Link Removed] algae[/URL]. The hormonal systems of many aquarium plants need that 12 hr (or longer) daylenghth. Otherwise, many plants think winter is coming on (short daylength) and they go into hiberation. That is, they collapse. "

Well, how does this work with a high light, high tech tank? Is it doable? Obviously, too much and too long photo period can cause algae issues.


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## talontsiawd (Oct 19, 2008)

I am not saying it's wrong or right but I have never heard of it. I have had a photoperiod that long but only on lower light, non high tech tanks. On the contrary, I doubt many of my high tech tanks would have worked at all with that photoperiod. 

I have never had any plants suffer from a shorter period, even in the long term. One thing that is nice if you can have a very long photoperiod is that your coloration can be much better than one may expect given the light output. 

In my experience the lower the light output, the easier it is to add hours to the overall photoperiod but I still start around 6 and up it until I start running into issues and rarely get past 8 to 10, depending on lighting.

However, I am much more curious to hear what others have to say.


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## roadmaster (Nov 5, 2009)

talontsiawd said:


> I am not saying it's wrong or right but I have never heard of it. I have had a photoperiod that long but only on lower light, non high tech tanks. On the contrary, I doubt many of my high tech tanks would have worked at all with that photoperiod.
> 
> I have never had any plants suffer from a shorter period, even in the long term. One thing that is nice if you can have a very long photoperiod is that your coloration can be much better than one may expect given the light output.
> 
> ...


 +one.
I started ass backward's with too much light for too long ,then went to shorter and shorter lighting period.
Was not until I reduced the intensity and duration that algae which hampered my previous effort's ceased to exist and plant's began to thrive and grow albeit slowly in low tech tanks.
Much easier I think to start with 6 hours and work up than to do the opposite in my opinion.


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## Jeff5614 (Dec 29, 2005)

Interesting topic by the OP. I think with a medium to lower light tank longer photoperiods are perfectly doable. High light tanks seem like they might be a bit more difficult with a longer photoperiod. I have a medium light 75g with relatively undemanding plants and do a 12 hour photoperiod with no problems.


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## thedarkfinder (Feb 29, 2008)

Not all lights are the same. 

If you have a very low par system, but really bright, you can have them on for long hours. But a high par, low light system, you need to shorten the period. 

So yes it is 100% correct, but useless information. Until you know all the factors that are in play, it is impossible to tell a person how long or how bright something is. 

A t5HO 1 year old bulb will have less lumens then a brand new t8. 

Your photoperiod should start at 6 hours and work up. I have one tank that gets over 14 hours of light a day, it does fine.


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## ReluctantHippy (Jun 23, 2011)

We're talking about tropical plants right... That tend to naturally occur around the equator? Where sunlight is capped to 12 hours max... And these plants reside next to the water which tends to be one of the few open spaces surrounded by tall tall trees that shade the bank (and plants) most of the day... I would call BS on this. Most all aquatic plants I've dealt with do fine with as little as 4 hrs a day of light given it's adequate strength.


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## latchdan (Sep 7, 2007)

I had terrible Green Dust algae and reducing photo period, increasing amount of plants and EI dosing almost got rid of my algae. Went from 10hr photo to 6hr.


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