how many hours of light per day is best for sprouts?

HanginIron said:

C3--I don't know this term

Click to expand...

well, google is your friend . heres a short explanation by ed rosedahl : One way in which plants are categorized is by the way they gather and handle carbon dioxide. Cannabis is a C3 plant. It uses the CO2 it gathers during the light period, when it is photosynthesizing. Plants designated C4 also gather CO2 during the dark period for use during the light period. Many C3 plants, including cannabis, do not need a rest period. They continue to photosynthesize as long as they are receiving light. The plant's photosynthetic rate determines its growth rate because the sugars are used by the plant to build tissue and for energy. Cannabis under continuous light will grow 33% faster than the same plants on an 18-6 light regime.


Then read this http://www.marietta.edu/~biol/biomes/photosynthesis.htm

then what is the difference? between c3 and c4?

The difference is between enzymes which accept CO2 from the air. C3 plants use enzym ribulosodiphosphatcarboxylase while C4 and CAM plants use phosphoenolpyruvatcarboxylase to accept CO2 from the air. Also the primary product of photosynthesis of C3 plants is phosphoglycerat while in C4 plants it is oxalacetate The differences are also between structure of the photosynthetic apparat. I hope this helps, also hope you know what enzymes are.

The difference occurs in photosynthesis. From the point of view of the first subsance created, there are 3 types of plants: C3, C4 and CAM
As protozoan pointed out C3 plants use RuDP carboxylase to fix CO2 and the first organic molecule created is phosphoglycerat(this thing has 3 C atoms=> the name C3)
C4 plants use PEP carboxylase to fix CO2 and the first organic molecule is oxalacetic acid(4 C atoms, from which comes the name). At the C4 plants photosynthesis is 6 times faster than C3 plants
There is a third kind, the CAM plants.

There are btw 10000 pages discussing this topic so there is a lot of info around. i have my preferances and other ppl have theirs. but when it comes down to biology, i really cannot see why anyone would vegg a C3 plant with only 18h lights on when you have 6+ hours of light/energy. it all comes down to biology.

mackdown said:

Great advice. What I have been doing is leaving them under the light in the evening and then just giving them natural sun all day. I have everything set up outside on my balcony, so at night I just slide them to the other side of the balcony where I have my lights and turn them on.

Click to expand...

want to be carefull using natural sulight this time of year as the sun is begining to become further and further away and will cause stretch. i keep my clones on 24/0 but i use 1 26w bulb above them and they are on the same outlet as my aero cloner.

HanginIron said:

C3--I don't know this term

Click to expand...

C3 is a classification for plants and how they breath I thought. Ie: some cactus actually breath at night instead of the daytime. But I still disagree a night cycle helps with root development. atleast thats what my observations seem to be. and yes it is also strain specific. but my cuts seems to root faster and are healthier with a night cycle. but again thats just me and the strains I have.

er0senin said:

well, google is your friend . heres a short explanation by ed rosedahl : One way in which plants are categorized is by the way they gather and handle carbon dioxide. Cannabis is a C3 plant. It uses the CO2 it gathers during the light period, when it is photosynthesizing. Plants designated C4 also gather CO2 during the dark period for use during the light period. Many C3 plants, including cannabis, do not need a rest period. They continue to photosynthesize as long as they are receiving light. The plant's photosynthetic rate determines its growth rate because the sugars are used by the plant to build tissue and for energy. Cannabis under continuous light will grow 33% faster than the same plants on an 18-6 light regime.


Then read this http://www.marietta.edu/~biol/biomes/photosynthesis.htm

then what is the difference? between c3 and c4?

The difference is between enzymes which accept CO2 from the air. C3 plants use enzym ribulosodiphosphatcarboxylase while C4 and CAM plants use phosphoenolpyruvatcarboxylase to accept CO2 from the air. Also the primary product of photosynthesis of C3 plants is phosphoglycerat while in C4 plants it is oxalacetate The differences are also between structure of the photosynthetic apparat. I hope this helps, also hope you know what enzymes are.

The difference occurs in photosynthesis. From the point of view of the first subsance created, there are 3 types of plants: C3, C4 and CAM
As protozoan pointed out C3 plants use RuDP carboxylase to fix CO2 and the first organic molecule created is phosphoglycerat(this thing has 3 C atoms=> the name C3)
C4 plants use PEP carboxylase to fix CO2 and the first organic molecule is oxalacetic acid(4 C atoms, from which comes the name). At the C4 plants photosynthesis is 6 times faster than C3 plants
There is a third kind, the CAM plants.

There are btw 10000 pages discussing this topic so there is a lot of info around. i have my preferances and other ppl have theirs. but when it comes down to biology, i really cannot see why anyone would vegg a C3 plant with only 18h lights on when you have 6+ hours of light/energy. it all comes down to biology.

Click to expand...

Thank you for taking the time to answer and providing the link. I have not done a side by side comparison, perhaps I should, but my plants seem to be healthier looking when given a rest period. 20/4 seems to work well for me.

Everyone has there way. I've tried all different. I find 24/7 lights the best through all of veg. Growth seems much better. And when it comes time to switch to 12/12 they start budding much faster. Just my 2 cents!

RetiredMatthebrute said:

18/6 is fine for sprouts or 24 is fine as well i personally dont like doing 24 hour lights on because i like my plants to have some dark time to do what plants do when its dark out in nature.

Click to expand...

I do not disagree that some varieties do better with a dark period in veg. I go either 20/4 or 18/6.Comparing outdoors to indoors does not make sense, they are apples and oranges. Indoor plants need a more consistent environment, no light leaks etcOutdoor plants have wildly fluctuating temps, humidity and get light in the middle of the night.