7 hours
photo period confusion
Well I always heard to have a night/lights-out for planted tanks, but of course that was for rooted plants in soil tanks. I get that a plant is alive and performing it's functions even in the dark, so I believed (and shared) the advise to have a dark time. If this supposition is not correct, what is the scientific evidence? Is down time just about the water CO2 level? And fish comfort?
What then is the ideal photo period for a rooted-plant NPT with fish inhabitants? Keeping in mind algae and any other important factors.
What then is the ideal photo period for a rooted-plant NPT with fish inhabitants? Keeping in mind algae and any other important factors.
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Not to worry.Well I always heard to have a night/lights-out for planted tanks, but of course that was for rooted plants in soil tanks. I get that a plant is alive and performing it's functions even in the dark, so I believed (and shared) the advise to have a dark time. If this supposition is not correct, what is the scientific evidence? Is down time just about the water CO2 level? And fish comfort?
What then is the ideal photo period for a rooted-plant NPT with fish inhabitants? Keeping in mind algae and any other important factors.
The scientific evidence that I have recently found shows that several aquatic plants will grow much better with a longer photoperiod (that is, 22 hr and/or continuous light). This information is very useful for those setting up refugiums (water purification systems using aquatic plants) and those that grow aquatic plants to sell.
For ordinary situations and NPTS, I would follow what CS-Gardener recommends. My own tanks run with a 14 hr day and a 4 hr siesta. Works great!
Lighting seems to be one of those things that 'just depends'. Light intensity, fertilization, Natural methods vs. high-tech, etc...
I read about dwalstad's split photoperiod once and tried it (14 hrs with a 4 hr rest) . I have to say I am very pleased with the results and I wouldn't change it. But I also know those who light for 7 hours, or 8, or 9, or 10...and everyone of them has great growth and healthy plants.
Very interesting info about continuous light and hygro and the alga. I have a 1 gallon "experiment station" at work on my desk. I think I'll try that with some mosses and plants and see what I end up with. I'll update if anything cool happens.
-Dave
I read about dwalstad's split photoperiod once and tried it (14 hrs with a 4 hr rest) . I have to say I am very pleased with the results and I wouldn't change it. But I also know those who light for 7 hours, or 8, or 9, or 10...and everyone of them has great growth and healthy plants.
Very interesting info about continuous light and hygro and the alga. I have a 1 gallon "experiment station" at work on my desk. I think I'll try that with some mosses and plants and see what I end up with. I'll update if anything cool happens.
-Dave
Now this is interesting!
Thanks for the input.There does seem to be an interesting bio-rhythm to algae. In addition to what you've written, the marine alga Gonyaulax polyedra bioluminesces in the dark, photosynthesizes in the day, and divides in the dark just before dawn. My textbook* goes on to say, "If Gonyaulax is kept in continuous light, these three functions continue to occur with the same rhythm for days and even weeks, long after a number of cell divisions have taken place."
As to aquatic plants, I would agree that some species may look different with continuous light, but that doesn't mean that they've decreased their productivity. If you can find a paper that compares growth rates/biomass production of aquatic plants that shows decreased growth with continuous light, I'd love to see it. So far, all I've found is either no change or a major (and statistically significant) increase.
*Raven PH, Evert RF, and Eichhorn SE. 1992. Biology of Plants (5th Ed.), Worth Publishers (NY), p. 578.
I was sent here from TPT forums (plantedtank.net) to get dwalstads' advice or input on something similar to this discussion, but instead of too much or long photo times, my interest is in the dark times.
Allow me to explain my thoughts. Outside nature is governed by itself on a 24 hour schedule, albeit sometimes changing, but nature has its' best benefit in mind I believe. In our aquariums, we are the governers, and decide what is best. (Or worst for the first few days I started planting my tanks)
If light is what encourages growth, tells our plants to start sucking up nutrients. At night they respire, and reach for the skies. (but I'm a soldier and value my sleep time)
What is the minimum downtime for plants? IS it possible and still healthy for a 9 hour on, 9 hour off cycle?
Quote from Naja when asked the same ? on TPT:
"Ok, it's sounds like you are wondering if we can "add more days to the year" by using a minimum dark cycle. I've pondered that--6 hrs On, 6hrs Off x2/day, etc. I don't know the answer, but I've pondered the thought."
Thank you for your time
Allow me to explain my thoughts. Outside nature is governed by itself on a 24 hour schedule, albeit sometimes changing, but nature has its' best benefit in mind I believe. In our aquariums, we are the governers, and decide what is best. (Or worst for the first few days I started planting my tanks
)If light is what encourages growth, tells our plants to start sucking up nutrients. At night they respire, and reach for the skies. (but I'm a soldier and value my sleep time)
What is the minimum downtime for plants? IS it possible and still healthy for a 9 hour on, 9 hour off cycle?
Quote from Naja when asked the same ? on TPT:
"Ok, it's sounds like you are wondering if we can "add more days to the year" by using a minimum dark cycle. I've pondered that--6 hrs On, 6hrs Off x2/day, etc. I don't know the answer, but I've pondered the thought."
Thank you for your time
Can you please give some examples as to wich plants you are referring to?
Ok so with the period of their 24hour cycle (outside of aquaria), plants decide how they grow at night?
During the day they soak up nutrients, and store them as food once broken down into something they can actually use. So I assume that it's safe to say, the growth rate is dependent upon the amount of nutrients stored readily as food, wich is dependent upon the light intensity, dependent upon the length of lighting time. Once lights are out, the plants grow in relation to amount of food stored? What is the ratio, term, length, timing of lights out time, when the plant says "Hey, look buddy, I just can't grow no more, show me the liiiiiiiiiiiiiiiiiiiight!"
Correct me if I'm wrong please.
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