Split Photoperiod

[adadkins1]

I have been reading and hearing a lot about a split photoperiod and the benefits so I am thinking I will give it a whorl. I want to know who on here has had experience with it and what you think about it. Does it scare the fish for the tank to suddenly go dark in the middle of the day? Have you seen it have an effect on algae?

 

[mfdrookie516]

It's not something I can explain. I was talking with jetajockey about it in chat one day. It doesn't make sense... but it has worked wonderfully for me. That's been MY experience with it. My BBA and GSA issues have gone away. I'm not sure what it is that causes it to work so well for me, but it is.

 

[Wy Renegade]

By split, I assume you mean splitting the photoperiod in a 24 hour period? I don't run it on any of my freshwater tank, but do currently have it running on my saltwater tank, and have for about 7 months now. Can't really say that I've seen an significant increase in growth over a standard photoperiod myself.

 

[mfdrookie516]

You assumed correctly... unless he is talking about something completely different. I run mine split 3 on, 4 off, 4 on. It's not for increased growth... it's for decreased growth, in algae though.

 

[Wy Renegade]

You assumed correctly... unless he is talking about something completely different. I run mine split 3 on, 4 off, 4 on. It's not for increased growth... it's for decreased growth, in algae though.

Thanks, I thought so. Interestingly enough I've run into the same idea on saltwater, but users there are always claiming increased growth of corals because of it. Haven't encountered much in regards to decreased algae growth either SW or FW. Curious, so I'll follow along.

 

[Philly33]

I use 4x4x4. Moderate growth and zero algae. I have a great cleanup crew as well. Ive been doing this for 6months and see great results. I took the advice from mdrookie.

 

[mfdrookie516]

What's funny is that I used to think that it gave the algae less light, by limiting it to 4 hours at a time... then jetajockey got in the conversation with me that night about it and everything he said makes sense. Algae should grow easier than plants... so why is it that my plants look (well, they did until I started neglecting them) great, but the algae is greatly limited? That's what neither of us could explain. If I recommend it, I always put a disclaimer that it is only my experience that I speak of, as it may not work for everyone. Perhaps he will chime in and give a good explanation of why, in theory, it shouldn't work. I agree with the 'theory' part... just can't figure out why almost everyone who has tried it has had great results.

One benefit in addition to the decrease in algae is that it gives more viewing time for the workin' man. They're on in the morning before going to work, and in the evening after work... and off for 4 hours during the day when nobody wants to look at them anyways.

 

[adadkins1]

That is another positive I know I would enjoy. Having the lights on for a "straight" period allows me to only enjoy my tanks for about 2 hours total. Whereas I could have 4 or more hours if I split it. I am currently going to try it on my 10g that I have had some algae in.

I would like to see what jeta says.

 

[roundar]

What's funny is that I used to think that it gave the algae less light, by limiting it to 4 hours at a time... then jetajockey got in the conversation with me that night about it and everything he said makes sense. Algae should grow easier than plants... so why is it that my plants look (well, they did until I started neglecting them) great, but the algae is greatly limited? That's what neither of us could explain. If I recommend it, I always put a disclaimer that it is only my experience that I speak of, as it may not work for everyone. Perhaps he will chime in and give a good explanation of why, in theory, it shouldn't work. I agree with the 'theory' part... just can't figure out why almost everyone who has tried it has had great results.

One benefit in addition to the decrease in algae is that it gives more viewing time for the workin' man. They're on in the morning before going to work, and in the evening after work... and off for 4 hours during the day when nobody wants to look at them anyways.

Perhaps algae begins to die, or starts a process that hinders growth, before plants in the dark. So plants are never "starting to die" or triggering a process that hinders growth simply because they are exposed to a few hours of darkness, whereas perhaps algae does. I would agree too that a big benefit of adjusting the lighting schedule is that you can have it come on when you're available to view the tank.

For anyone with lots of planted tanks, as always, I'd love to see an experiment with varying light frequencies. Everything from constant 12h+/day to on/off every 15-30 minutes.

 

[aqua_chem]

Purely conjecture, but....

I've heard that plants are most photosynthetically active during the initial part of the photoperiod, gradually sloping off as the "day" goes on. During this inititial period, plants would probably easily out compete algae, but algae would be able to out-compete the plants later in the day when plants are less active.

I would imagine that this slow decline in activity is a result of some sort of a feedback loop that prevents the plant from making more sugar than the plant can reasonably process, thereby wasting the plants resources, both energetic and otherwise. Thus, after the plant has built up excess sugars during the earlier parts of the day, it slows down. Hypothetically, if you put a four hour gap between smaller photoperiods, the plants would have had a chance to process its excess sugars, thereby eliminating the feedback inhibition. Thus, the plant would enter the second photoperiod at full tilt again.

 

[Wy Renegade]

What's funny is that I used to think that it gave the algae less light, by limiting it to 4 hours at a time... then jetajockey got in the conversation with me that night about it and everything he said makes sense. Algae should grow easier than plants... so why is it that my plants look (well, they did until I started neglecting them) great, but the algae is greatly limited? That's what neither of us could explain. If I recommend it, I always put a disclaimer that it is only my experience that I speak of, as it may not work for everyone. Perhaps he will chime in and give a good explanation of why, in theory, it shouldn't work. I agree with the 'theory' part... just can't figure out why almost everyone who has tried it has had great results.

One benefit in addition to the decrease in algae is that it gives more viewing time for the workin' man. They're on in the morning before going to work, and in the evening after work... and off for 4 hours during the day when nobody wants to look at them anyways.

Indeed, and that is the benefit I enjoy most in regards to my personal reef tank.

Purely conjecture, but....

I've heard that plants are most photosynthetically active during the initial part of the photoperiod, gradually sloping off as the "day" goes on. During this inititial period, plants would probably easily out compete algae, but algae would be able to out-compete the plants later in the day when plants are less active.

I would imagine that this slow decline in activity is a result of some sort of a feedback loop that prevents the plant from making more sugar than the plant can reasonably process, thereby wasting the plants resources, both energetic and otherwise. Thus, after the plant has built up excess sugars during the earlier parts of the day, it slows down. Hypothetically, if you put a four hour gap between smaller photoperiods, the plants would have had a chance to process its excess sugars, thereby eliminating the feedback inhibition. Thus, the plant would enter the second photoperiod at full tilt again.

Interesting concept. Wonder if anyone has done anything with photoperiods of plants vs. algae.

With all the gardeners that are out there, you would think somebody would have done something with this already.