Personally I've had success both ways. I have a hard time swallowing the idea that something as simple as algae can remember how long the light has been on, and needs a period of darkness to rest - however this is how it is in nature, so turning the light off for 12 hours won't hurt the algae, you just go 12 hours without the algae growing and sucking up pollutants.linusfishing;3636080; said:
Mega Powerful Nitrate and Phosphate Remover - DIY!
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I actually think there's more consolidated info in this thread than one can easily find on algaescrubber.net, but there definitely IS some stuff there that's not covered here.Toddo;3636097; said:
It would be interesting to see if you had better luck with a 16/8 or 20/4 cycle than 12 on 12 off. I'm no more biologist than any of us in this hobby, but plants use photosynthesis to create energy, and in those periods of dark they dedicate themselves to expending that energy in the form of root growth, cell repair, etc. Sure they can grow while photosynthesizing but I can't say without reading a textbook or doing the experiment which is b etter. Wasn't it Zennzzo who found his did better outside if it wasn't in direct light?
Typically, the light cycle is 6 on 2 off for normal respiration.
<<In the presence of light, respiration and photosynthesis can occur simultaneously in algae. However, the respiration rate is low compared with the photosynthesis rate, resulting in a net consumption of carbon dioxide and production of oxygen. In the absence of light, algal respiration continues while photosynthesis stops, resulting in a net consumption of oxygen and production of carbon dioxide.>>
I believe it is thought that the first hour of lights off is the most effective, and net consumption tapers off after that. Thats why the off period is only two hours. (I no botanist though)
I do know that all plants need to see a light cycle.
<<In the presence of light, respiration and photosynthesis can occur simultaneously in algae. However, the respiration rate is low compared with the photosynthesis rate, resulting in a net consumption of carbon dioxide and production of oxygen. In the absence of light, algal respiration continues while photosynthesis stops, resulting in a net consumption of oxygen and production of carbon dioxide.>>
I believe it is thought that the first hour of lights off is the most effective, and net consumption tapers off after that. Thats why the off period is only two hours. (I no botanist though)
I do know that all plants need to see a light cycle.
Interesting but... many people have had great success with simply leaving the lights on 24/7, so saying the algae NEEDS a light cycle is inaccurate - it may yeild better results, but it's not necessary.Toddo;3637379; said:
All your excerpt says to me (where did you find that, by the way??) is that the algae consumes CO2 while the lights are on, which is fine by me.
I've been reading about algal cultures for biofuel and for scrubbing of flue gasses - and the bioreactors used in these installations are polycarbonate tubes that the flue gasses bubble upward while the water flows downward. What's interesting about this is that they somehow avoid the algae growing on the walls of the tube and blocking the sunlight. This would be cool to try in an aquarium, but it also presents another problem - you don't want the free floating algae in the water column, so you'd have to somehow filter it out.
Yet another interesting tidbit - biofuel algae farms use ponds and agitate the water to avoid overexposing the algae to sunlight - this seems opposite to what everyone has had success with using these tank scrubbers - it's hard to get too much light on a screen, even if you leave the lights on.
A lot of them use "glow plates": http://en.wikipedia.org/wiki/Glow_plate <- one of those may be interesting to use in a scrubber if they are not uber expensive.
A lot of them use "glow plates": http://en.wikipedia.org/wiki/Glow_plate <- one of those may be interesting to use in a scrubber if they are not uber expensive.
Interesting point from this quick little news story is the use of "floating algae mats" to treat the wastewater flowing through. I wonder how exactly they cultivate and maintain a floating algae mat, cuz that would be a lot easier to manage in a sump than a vertical screen.
http://www.sonoma.edu/pubs/newsrelease/archives/001122.html
http://www.sonoma.edu/pubs/newsrelease/archives/001122.html
And, (OK this is the last one, I promise!) a long presentation on wastewater treatment, but the takeaway here is that Algae thrives with a 50:8:1 Carbon:Nitrogen
hosphate ratio. I'm not sure what kind of waste ratios fish produce, but some algae systems may be made dramatically more effective by increasing the CO2 content (which we all should know cuz the planted guys all use CO2).
http://www.nrel.gov/biomass/pdfs/lundquist.pdf
hosphate ratio. I'm not sure what kind of waste ratios fish produce, but some algae systems may be made dramatically more effective by increasing the CO2 content (which we all should know cuz the planted guys all use CO2). http://www.nrel.gov/biomass/pdfs/lundquist.pdf
I found that while Googling "Algae Respiration". I think it was www.lagoonsonline.com.cvermeulen;3637481; said:
I haven't read about anyone leaving the lights on 24/7... do you have any forum post links about that and the success/failure anyone had?
You're doin' some good research there....btw!!
