JustDavidP's Seahorse Corral and Sump Project

[Reefbaby]

John - the major reason for doing reverse photoperiod is to create an environment with more stable pH and no fluctuations that are pretty typical in most tanks.
When the lights are on and photosynthesis is occuring, carbon dioxide is taken up by the macroalgae, oxygen is released and and this creates a rise in pH.
When the lights are off, respiration from all those photosynthetic organisms gives off carbon dioxide which causes pH to decrease. A reverse light cycle will at least partially offset pH swings.

Dave - I, personally, would agree with you. I think it's better to give organisms (and I mean ALL organisms) as much of a realistic setting as possible and although the lights may be on in a reverse fashion, they are still getting their "down" time as well.

[Rob]

john,
regarding the natural state, you are replicating it..

a common misconception to new comers is that your tank should be lit while the suns up.. makes sense right? the sun comes up, the lights should go on...

well the one thing that missed here is that it doesn't matter the "real" time of day, you just have to regulate the time in your tank.

for example, in my tank my lights don't start to come on till 11:00 AM the MHs don't come on till 2:00 PM... the last of the lights shut off at midnight...
so to my tank, 11:00 am is day break for the tank... and midnight is sunset for the tank... its the consistency that counts not the actual time

now to relate that to your fuge, its the same thing. since it s separate tank, its independent. for the fuge day break would start at 11:00 PM and sunset would be at 10:00 AM the next morning... how it relates to the tank, or the real sun for that matter doesn't matter... as long as it gets a consistent photo cycle as dave outlined...

hope that makes sense, sorry for the ramble..

[JustDavidP]

John,

I found that my macros grow under just about ANY lighting. I have C. Serrulata and Chaetomorpha that is growing in a 10 gallon tank with a standard AGA plastic hood and the silly little 15W bulb that comes with it. I have no idea what spectrum that is, but it is pretty "white". I also have it growing in my 26 Bowfront under 110W of mixed full spectrum and actinic. (55W actinic03 and 55W full spectrum) In my Sump-zilla, it is growing under a 65W Lights of America fixture at 6500K. Chaeto grows well for me under this same lighting.

I think 65K is just fine for growing plants and macro algae. It is real yellow/green and not very pleasing light to the eye (my eye anyway) but in a sump or fuge...who cares? As long as it is growing right?

Reverse photo period is simple and looks like this on paper:

10:00 AM - Display lights on*
10:00 PM - Display lights go off
10:00 PM - Refugium lights turn on
10:00 AM - Refugium lights turn off

*Some folks have their display lighting such that actinic lighting comes on first, then MH..and at the end, MH shuts off first, and an hour or so later, actinics shut off. Whatever works for you, or whatever your system is built to do. My display does NOT have independent switching for MH and Actinic. My old reef did.

In this scenario, SOME part of your system is illuminated 24/7. This keeps the pH swings to a bare minimum.

During the "light phase" when macro is using the light to photosynthesize, the macro uses CO2 and in the end, creates a byproduct...Oxygen. This is a good thing. However, the decrease in CO2 and related increase in O2 means and increase in pH. This level in your system during the "Day" is, or should be, in and around 8.2 correct? This is what you check against with your kits. However, during the dark phase, the opposite happens. CO2 is expelled and O2 is consumed. This causes a drop in the pH. Test your system in the middle of the day, and again well after the lights have shut off, and you will see the difference yourself.

By keeping a second "chamber" that is lit opposite of that within your display, you are in essence, creating a system whereby one part of the cycle is happening in area A, while the second is occurring in section B. This creates a "wash" of sorts where the pH should remain constant throughout the system.

Does any of this make sense to you? I'm kind of just regurgitating what I think I know

Here..this will really confuse us 6H2O + 6 CO2 + energy --> C6H12O6 + O2

Dave

[JustDavidP]

Wow I had to take the laptop into a meeting... a boring one at that... and was hammering out my reply during that meeting. Who'da thunk that all you folks would jump all over this topic

John...they are all "correct" and as a matter of fact, layed out their answers quickly and clearly I, on the other hand, rambled...and could cause some confusion.... skip over my volume of detritus and listen to the masses. They've "Got it goin on"

Dave

[DJGonzo69]

Dave, Christi & Rob,
Makes it all clear. Lots of great info!!! I will do a test comparison to see my PH when lights are on & when they are off. Gotta get another timer. Man I should buy stocks in these things..LOL

[JustDavidP]

Originally Posted by DJGonzo69

Makes it all clear.

really? When I read my own posts..I became confused

Glad to help!

Dave

[DJGonzo69]

Clear as a 10K MH :-)

[AdamJ]

6H2O + 6 CO2 + energy (light) --> C6H12O6 + O2 =durign "day" (algae)
02 + C6H12O6 --> 6H2O + 6CO2 + Energy (ATP)= All the time (everybody)

since you can see that you are only producing O2 (and using CO2) durign the day in your tank, and your usign up that O2 and creatign CO2 all the time, it is obvious that the reactions will not be balanced for the 24hr period. this inbalance, could result in a neagtive effects in your tank over a period of time, and you would be forced into makign constant ajustments to your water.

the reverse photo period allows for your refigium to balance this with its production durign the night period of your main tank. so basically in essence the equations become equal and its all good.

[Rob]

lol.. dave, i had a feeling you would get into a detailed response (which is a good thing, that i also enjoy reading) so i figured i would try to get some main points out to get the basic understanding there...

[DJGonzo69]

So is it a good idea to make the size of your fuge as close as possible to your display tank, so that the O2 & CO2 production is even? Especially when you are trying to counter react each other to make it a wash?

[Rob]

don't get me wrong, bigger is better, but the water volume is not directly related..

remember, your fuge is going to be packed with photosynthetic macro algae, and there will be much more photorespiration per gallon, than in your tank.

so while having a large fuge is a better thing, its not a "requirement"