Reverse lighting cycle on refugium?
- Thread starter JoeESSA
- Start date
oldsaltman
New member
Reverse lighting keeps your PH more balanced. 
My dad has had a box of Chaeto on 24/7 lighting for over a year now. It's used for growing out lettuce slugs. It doesn't have any die off. They seem to like it as much as Bryopsis. I haven't quantitatively studied growth rate of 24/7 vs half day lighting for Chaeto but my guess is it grows faster on 24/7.
The only study I have ever seen on 7/24 lighting was on terestrial plants and continuous lighting produced lower overall growth.
I do not know of any studies on marine algaes. Years ago NASA did a series of experiments aimed at growing single celled algae in space. I seem to remember the algae did best in an environment where it was rotated into and out of a light field.
Fred
I do not know of any studies on marine algaes. Years ago NASA did a series of experiments aimed at growing single celled algae in space. I seem to remember the algae did best in an environment where it was rotated into and out of a light field.
Fred
Well, you know 24/7 lighting is not a naturally occuring environment. I would somehow expect that the algae would benefit from having a natural lighting cycle. I believe they consume CO2 during the day and produce O2 during the night or something like that. I can't quite remember my school biology. Just seems unnatural to expose marine algae to light 24/7...
Dr Begalke
In Memoriam
"Interestingly, three marine microalgae, Skeletonema costatum, Phaeocystis globosa and Emiliania huxleyi,24 were studied for their rates of photosynthesis and carbon uptake mechanisms in continuous light vs. those same species in light/dark cycles (12 h on/12 h off and 16 h on/8 h off). The rates of photosynthesis were nearly twice as high with light/dark cycles as with continuous lighting. In two of the species (S. costatum and E. huxleyi), but not the third, the contribution of bicarbonate to the total carbon uptake increased dramatically in light/dark cycles compared to continuous light.
How this result might relate to growth and nutrient uptake in lit refugia where macroalgae are often grown to export nutrients is not known. However, it is a sign that perhaps continuous light is not optimal, in addition to being more expensive."
I wouldn't use 24/7 lighting.
How this result might relate to growth and nutrient uptake in lit refugia where macroalgae are often grown to export nutrients is not known. However, it is a sign that perhaps continuous light is not optimal, in addition to being more expensive."
I wouldn't use 24/7 lighting.
bureau13
New member
The only solid reason I've ever heard for using 24/7 lighting on a macroalgae refugium is when the macro in question is caulerpa...supposedly the 24/7 lighting is supposed to prevent it from "going sexual" and releasing a bunch of nutrients back into the water. Since I started using chaeto, I've gone to a reverse daylight schedule, and the stuff seems to be growing well. The guys at wetwebmedia seem to be proponents of the reverse daylight schedule which convinced me to go that way.
jds
jds
I had marine botany years ago, like 10+, and the professor discussed C3 and C4 plants. I cannot remember all of the details and don't have the textbook since it was $120 back then, but one of the two types needed a dark phase.
I wish I could be more helpful but that knowledge has been replaced with useless triva. Maybe post in the plant forum.
I wish I could be more helpful but that knowledge has been replaced with useless triva. Maybe post in the plant forum.
I have been using 24/7 lighting so far. I have both a Caulerpa species and chaetomorpha in my fuge. The Caulerpa grows very well, but the Cheato has little growth. I have now harvested out most of the Caulerpa to see if this would help the Chaeto to get a foot hold, but I still don't see significant growth with the Chaeto whilst the Caulerpa left in the fuge is bouncing back. This is the reason I am speculating about possible benefits of introducing a dark/light cycle...
It could be that the Caulerpa likes the 24/7 lighting and the Cheato doesn't. But keep in mind that Caulerpa will grow a lot faster than Cheato in any circumstance.
I have seen Caulerpa bloom in 24/7 lighting. I have never seen it bloom if it is regularly harvested/trimmed or eaten by fish.
If heavily relieing on Caulerpa, use several diferent varieties so they will not all go to seed at once. It's not the bloom itself that pollutes the water. It's the subsequent lack of plants that is the problem (ie you only had one type of caulerpa and its all gone.)
I know Cheato doesn't need a dark cycle, but I could be wrong about it growing faster in 24/7 lighting. I've never measured it.
I have seen Caulerpa bloom in 24/7 lighting. I have never seen it bloom if it is regularly harvested/trimmed or eaten by fish.
If heavily relieing on Caulerpa, use several diferent varieties so they will not all go to seed at once. It's not the bloom itself that pollutes the water. It's the subsequent lack of plants that is the problem (ie you only had one type of caulerpa and its all gone.)
I know Cheato doesn't need a dark cycle, but I could be wrong about it growing faster in 24/7 lighting. I've never measured it.
All this really stems from a nitrate issue I have been trying to resolve. My nitrate is at 20ppm and I haven't been able to get it stable at a lower value than this. I don't want to turn this into a "help, I have a nitrate issue" discussion, but was considering the possibility that if I could increase the growth of my Chaeto it may help. I also wanted to remove the Caulerpa in case it was contributing to the nitrate by going asexual. Having said that, I don't actually know what the visible signs are when Caulerpa goes asexual. The pieces that I pulled out did have a lot of clear, egg-like buds on them. I had seen a couple of posts on reverse lighting scheme, so that's why I started this thread, to explore this option further...
When caulerpa goes sexual, the entire plant will go clear in a short period of time and your tank will get very cloudy.
With such high nitrates, I doubt your caulerpa will go sexual. This event is triggered by a lack of nutrients for the plant to keep going, so it reproduces.
I have found that growth rates of chaeto and caluerpa seem to vary over time. Most of the time, caulerpa grows faster for me, but my chaeto has shown busts of growth at times.
I would let the algae full the fuge and then harvest smaller amounts once or twice a week. You want as much algae biomass sucking up nitrates as possible.
Fred
With such high nitrates, I doubt your caulerpa will go sexual. This event is triggered by a lack of nutrients for the plant to keep going, so it reproduces.
I have found that growth rates of chaeto and caluerpa seem to vary over time. Most of the time, caulerpa grows faster for me, but my chaeto has shown busts of growth at times.
I would let the algae full the fuge and then harvest smaller amounts once or twice a week. You want as much algae biomass sucking up nitrates as possible.
Fred
pjf
Premium Member
pH stability
pH stability
The rationale for reverse daylight photosynthesis (RDP) is to provide oxygenation and carbon dioxide uptake at night. At night, the carbon dioxide level in the main tank tends to rise and lower the pH. By stabilizing the CO2 level with an RDP refugium, the pH is also stabilized.
pH stability
The rationale for reverse daylight photosynthesis (RDP) is to provide oxygenation and carbon dioxide uptake at night. At night, the carbon dioxide level in the main tank tends to rise and lower the pH. By stabilizing the CO2 level with an RDP refugium, the pH is also stabilized.
I offset the lighting schedules to balance ph. You can try adding some iron to boost your chaeto morpha growth. Mine took off when I starting adding coral vital which has some iron in it. I did three things at the same time when I tried to get my nitrates below 20. Purchased a clam added chaeto to my fuge and started poring the fish food through a net first so the food just went in and not all the juice. Unfortunately I don't know which worked but have not seen my nitrates above zero since.
