# split photoperiod lighting?



## naturelady (Dec 14, 2009)

I'm wondering about the benefits of split photoperiod lighting (turning the lights off for a few hours during the middle of the day). The theory sounds good- it lets the CO2 build up again so the plants have plenty of nutrients for photosynthesizing when the lights are on. Are there any other benefits for it? I know some people love it- could you guys speak up and share your experience?

My tank is a 29 gal moderately planted, lightly stocked tank. I keep it as low tech as possible, but there definitely is a threshold of minimum amount of maintenance I must do. If I let the ferts get too low, or forget to do a water change for too long, or forget to refresh my DIY CO2, etc, the algae starts growing with a vengeance. Of course, its mostly BBA (about the ugliest algae there is). I'm looking for another thing to add to my arsenal to help the plants so that rather than being just barely ahead of the algae, they have a little more of a head start in growth.


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## bikinibottom (Nov 18, 2012)

I started a thread on this topic over in the lighting section ("siesta" in the subject line) -- might want to check there for some interesting input. Do you have Diana Walstad's book? She has a page in there about it, including a graph that shows CO2 levels in the tank using a siesta and not using a siesta. As you mentioned, the graph indicates that the CO2 is replenished during the siesta. She argues that it does help reduce algae, but I think the jury is still out on that. Some say they do a split photo period and as a result have no algae, some say they do it and it didn't make a difference. There are probably too many variables on various tanks to say definitively that it's the split photo period that contributed or not. My current tank has been up for 2 months (withOUT a split photo period), and I have yet to see any algae. I went a month without cleaning the glass -- no algae. I just wiped it today -- pointless, because there was nothing on there. So when I switch to a split photoperiod I won't have any input to add about the impact on algae (unless I suddenly start growing some!)

Not sure how this works with CO2 injection. I am starting to try this regime on my low-tech tank (I dose Excel every day, but no CO2). Seems that the benefit of CO2 replenishment is kinda moot if you do CO2.


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## Razorworm (Jul 24, 2011)

My lights come on at 530am and go off at 10am. They come on again at 2 and off at 7pm. All dirt, low tech. Good plant growth ( slow compared to hi tech) no algae to speak of.


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