Macro Algae Photo Period

[prow]

i had to open my big mouth didn't i. ok like most things in the hobby only part of a cycle is known. in photosynthesis there are two parts, the first part is photosystems and the second is the Calvin Cycle(carbon fixation). other cycles get involved. here i am refering to the Calvin cycle, the second part of photosynthesis(sugars/starches) and photoinhibition(reduction of photosynthetic rates) and the xanthophyll cycle(uses Cadmium inhibits epoxidation of diatoxanthin/ its a regulatory mechanism involved in stress response).
nycthemeral cycles even come into play but, with out getting too into it, because then i would have to go into bio/orgainic chem, with all the eletrons added in to mess.
so in short during the day H20 and startchs are taken in and stored, O2 is produced from these proccesses. at night CO2 is taken up(the carbon source) and the starch is turned to sugar(energy) and used in the tissues for growth. this does occur during photoperiods but with a dark period, faster growth rates result. basically plants store energy during photoperiods and use it for growth at night. the xanthophyll cycle is a compensating mech used to slow photoinhibition during times of stress ie,..high levels of UV radiation and/or PAR levels. compesating mech get used up. perhaps why you hear about people having issues with sudden stoppings of growths or shrinking and disolving issue with cheato after long periods of time. with a dark cycle photosynthesis is more efficient and no unused starches and sugars are released. as a little bonus this is were phosphate bonds are broken to make matters even better there are three stages in the calvin cycle.
a diagram or two.



here are a couple links to what i am talking about. the calvin cycle also adds other organic product aside from sugar. way to tired to go all into this but here are a few link to check out.
Photosynthetic Dark Reaction
Chemistry for Biologists: Photosynthesis

[goody]

So how long should I run my fuge light? What are the benefits of running it on opposite timing of main tank? Also, how often should I trim my cheato? My fuge section is only 10"x11" I believe.

[prow]

i would run it about 12 hour oppisite your main tanks photoperiod. benefits are decreased ph swings and if your trying to get some zooplankton(pods and things) production out of your refugium a dark period really helps. for 24/7 lighting it might be fine, although its not as efficient without a calvin cycle and you spend IMO unesseccary money on electricity and bulbs not to mention it will not be much in the way of competing with other algaes in your main tank that are getting a clavin cycle, because the algaes in the main tank will be uptaking the CO2(carbon) that is present during dark period(imo your algae in teh sump should take care of another reason why no 24/7), something has to deal with it but it still may grow enough for your exporting needs.
trim it when you think there is too much and/or if it impedes flow.

the 24/7 lighting is really just for caulerpa because of it going sexual on you. for some its worth the reduction in growth rate to avoid that risk.

[Frankie]

Great explanation Prow! I love the diagrams. They help a numb numb like me a lot in understanding what your trying to teach here.
I am going to go back on the 12/h cycle and watch the growth rates with my cheato and mangrove for a month and then back to 24/7 for a month to see the difference. I will take pictures. Here's one today after cutting my cheato back. It works out well being the first of the month. Remember this is a two year old refugium. I cut the cheato back two days ago. It was twice this size.

[prow]

might want to try each way for a couple months but only measure growths the second month, allow some adaption time.

if you remeber, post the results here, so i dont miss it

one thing i left out, a way to put it in a nut shell with 24/7 lighting the xanthophyll cycle kicks in (slows photoinhibition during times of stress, extended photoperiods) the energy and resourses used for slowing photoinhibition could be use for growth instead, if/with a dark period allowed.

[BarbMazz]

There's prow lookin' all smart again and everything.

Another helpful post about the Calvin cycle, thanks!

[jhnrb]

Well done Prow. Nothing to add.

[prow]

thanks

o hey frankie, to get a good comparison, weigh the cheato you have right now and leave your lighting on 24/7 for the next month. then weigh it in say 30 days. switch the lighting to a 12hour photoperiod and some new cheato and keep it under that for a few months then trim to match the beginning weight of the 24/7 cheato ball wait the same time frame and weigh it again. the reason;

couple things ro note; should weigh it dont go by looks. it may grow thicker or tighter.
also reason to get new cheato for the 12hour photoperiod, if it been there for awhile. not sure how long its been under 24/7 lighting, but it has been shown that prolonged periods of UV/PAR dose causes DNA changes/damage and other things. just to keep in mind.

[Woodstock]

(Copied here and made it a stickie)

[elliottb]

Just something to add about the photosynthesis, When there is light that is captured by an organism, it is chemical bond energy. This bond needs to be broken by the cell. This is where the ATP (Adenosine triphosphate) and ADP (adenosine diphosphate) come in. When the chemical bond is released it gets captured by high energy phosphate bonds (~P). Then the ~P combines with ADP and forms ATP which is the source of energy for cellular work.

I am currently studying biology in school incase you were wondering why I knew this.

[prow]

hey elliottb how goes it. best of luck to you on your class. you sure picked the right hobby, class should be a breeze

[elliottb]

Originally Posted by prow

hey elliottb how goes it. best of luck to you on your class. you sure picked the right hobby, class should be a breeze

I certainly(sp?) hope so! My last semester consisted of aviation, but chose to switch, so now I basically have to start form scratch with bio.

[BengBear]

Does having sufficient magnesium in the water promote growth of grape caulerpa remosa?

[prow]

no, Mg+ does not promote its growth. low levels may lead to toxicity of metals like Zn. it helps with ion exchange, its needed but does not promote growth.

[Triggerjay]

So what happened to frankies experiment? Hey prow, I have a Q for you... Most run a reverse lighting schedule on the fuge, to help prevent large PH swings,.... BUT when the macro grows (while lit) it produces oxygen. Wouldn't you want this to produce the oxygen during the day when the main tanks metabolism is at it's highest, to provide as much oxygen as possible for fish, corals, etc? I run about the same lighting schedule on the fuge as I do the display. I have little in the way of a PH swing. maybe .1 at the most. I used to always run my fuge reverse cycle, but changed my thinking on this theory. what are your thoughts on this?

Jason