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 t0ad
ribbit ribbit
Registered: 09/28/08
Posts: 599
Loc: FL, USA
Last seen: 15 years, 15 days
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 Re: 18 vs 24 Hours of Light in the Vegative Cycle  [Re: Sirius]
#128453 - 10/03/08 04:03 PM (16 years, 1 month ago) |
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yeah wikipedia had that neat little chart, so you could say I borrowed it from them.
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<img src="/forums/images/graemlins/hypnotoad.gif" alt="" />
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erb
Registered: 04/20/08
Posts: 198
Last seen: 13 years, 8 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: t0ad]
#132661 - 10/15/08 09:35 AM (16 years, 28 days ago) |
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If anyone plans on doing a 18/6 - 24/0 comparison remember the other variables involved, heat and Co2.
There is no point in going 24/0 if your not supplying the the plant with enough Co2 and keeping your heat low enough to prevent stretching.
There are other variables that must be taken into account if you want to do a true scientific experiment.
Some people will see better growth with 18/6 for two simple reasons. One is less heat, two is the average Co2 level will be higher. if your not supplementing your Co2 or venting good enough, more hours of light wont make much of a difference, the rest of the plants needs must be met to take advantage the increase in light.
This also includes an increase in water and nutrient needs.
Complicated scientific terms are great if they can be understand and utilized, but that is not the case here, it's unnecessary and causes unneeded confusion for the majority of people.
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erb
Registered: 04/20/08
Posts: 198
Last seen: 13 years, 8 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: erb]
#132682 - 10/15/08 11:12 AM (16 years, 28 days ago) |
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For those that are interested in the scientific aspect, I found this explanation of the Calvin cycle helpful.
The Calvin Cycle:
ATP and NADPH produced by the light reactions are used in the Calvin cycle to reduce carbon dioxide to sugar.
The Calvin cycle is similar to the Krebs cycle in that the starting material is regenerated by the end of the cycle.
Carbon enters the Calvin cycle and leaves as sugar.
ATP is the energy source, while NADPH is the reducing agent that adds high energy electrons to form sugar.
The Calvin cycle actually produces a 3 carbon sugar glyceraldehyde 3-phosphate.
The Calvin cycle may be divided into 3 steps.
Step 1: Carbon Fixation. This phase begins when a carbon dioxide molecule is attached to a 5 carbon sugar, ribulose biphosphate (RuBP).
This reaction is catalyzed by the enzyme RuBP carboxylase (rubisco) one of the most abundant proteins on earth.
The products of this reaction is an unstable 6 carbon compound that immediately splits into 2 molecules of 3-phosphoglycerate.
For every 3 molecules of carbon dioxide that enter the cycle via rubisco, 3 RuBP molecules are carboxylated forming 6 molecules of 3-phosphoglycerate.
Step 2: Reduction. This endergonic reduction phase is a 2 step process that couples ATP hydrolysis with the reduction of 3-phosphoglycerate to glyceraldehyde phosphate.
An enzyme phosphorylates ( adds a phosphate) 3-phosphoglycerate by transferring a phosphate from the ATP. The product is 1-3-bisphosphoglycerate.
Electrons from the NADPH reduce the carboxyl group of the 1-3-bisphosphoglycerate to the aldehyde group of glyceraldehyde-3-phosphate.
For every three carbon dioxide molecules that enter the Calvin cycle,6 glyceraldehyde-3-phosphates are produced, only one can be counted as a net gain. The other 5 are used to regenerate 3 molecules of RuBP.
Step 3: Regeneration of RuBP. A complex series of reactions rearranges the carbon skeletons of 5 glyceraldehyde-3-phosphate molecules into 3 RuBP molecules. These reactions require 3 ATP molecules.
RuBP is thus regenerated to begin the cycle again.
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Yrat
Happy Planting
Registered: 04/20/08
Posts: 886
Last seen: 10 years, 9 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: erb]
#132724 - 10/15/08 12:37 PM (16 years, 28 days ago) |
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Quote:
erb said:
Step 1: Carbon Fixation. This phase begins when a carbon dioxide molecule is attached to a 5 carbon sugar, ribulose biphosphate (RuBP).
 
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 "Prohibition will work great injury to the cause of temperance. It is a species of intemperance within itself, for it goes beyond the bounds of reason in that it attempts to control a man's appetite by legislation, and makes a crime out of things that are not crimes. A Prohibition law strikes a blow at the very principles upon which our government was founded." - Abraham Lincoln
"There are a thousand hacking at the branches of evil
to one who is striking at the root"
~ Henry D. Thoreau
Strike The Root
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erb
Registered: 04/20/08
Posts: 198
Last seen: 13 years, 8 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: Yrat]
#132974 - 10/15/08 11:19 PM (16 years, 27 days ago) |
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There are several stages in the progress of the carbon dioxide. It boils down to vocabulary. Just like any chemical reaction you have the reactants and the products. Everything else is just fine tuning.
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BulkBread
Registered: 02/24/09
Posts: 31
Last seen: 15 years, 6 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: Sirius]
#219970 - 04/26/09 07:05 PM (15 years, 6 months ago) |
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Bump
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 Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal 
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: BulkBread]
#219988 - 04/26/09 08:05 PM (15 years, 6 months ago) |
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ummm....why? please don't bump threads unless you actually have something productive to add to the conversation. This was pointless.
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therealziz
Registered: 04/25/09
Posts: 1
Last seen: 15 years, 2 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: Harry_Ba11sach]
#220008 - 04/26/09 08:33 PM (15 years, 6 months ago) |
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whats bumping?
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MFDoom666
trash hoarder
Registered: 04/24/08
Posts: 8,842
Loc: emerica
Last seen: 6 years, 11 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: therealziz]
#220018 - 04/26/09 09:13 PM (15 years, 6 months ago) |
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bringing an old post back to life.
only retards do it.
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FurrowedBrow said:
They should teach african engineering at the college level. mcgyver 101
Harry_Ba11sach said:
Has anyone really been far even as decided to use even go want to do look more like?
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erb
Registered: 04/20/08
Posts: 198
Last seen: 13 years, 8 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: MFDoom666]
#225587 - 05/12/09 02:32 PM (15 years, 5 months ago) |
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Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: erb]
#225590 - 05/12/09 02:35 PM (15 years, 5 months ago) |
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Oh hey look who it is, the guy who was really really wrong in this thread
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Yrat
Happy Planting
Registered: 04/20/08
Posts: 886
Last seen: 10 years, 9 months
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Re: 18 vs 24 Hours of Light in the Vegative Cycle [Re: erb]
#225630 - 05/12/09 04:33 PM (15 years, 5 months ago) |
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nice plant
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"Prohibition will work great injury to the cause of temperance. It is a species of intemperance within itself, for it goes beyond the bounds of reason in that it attempts to control a man's appetite by legislation, and makes a crime out of things that are not crimes. A Prohibition law strikes a blow at the very principles upon which our government was founded." - Abraham Lincoln
"There are a thousand hacking at the branches of evil
to one who is striking at the root"
~ Henry D. Thoreau
Strike The Root
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