gaetanocallista
New member
yes, but probably this is not secondary!
So, 6 h MH without actinics is different from 6 h MH with 100 or 200 w actinics or more
shorter photo period = faster growth
- Thread starter Ace1
- Start date
So, 6 h MH without actinics is different from 6 h MH with 100 or 200 w actinics or more
IndyReefMan
New member
One of the first books on reef keeping that I ever read was "Marine Reef Aquarium Handbook" by Robert J. Goldstein. It's still one of my favorites and I've read most all of them. In this book, the author states that Metal Halide lighting should only be run from 4 to 6 hours per day. Any more than that is wasted electricity and just contributes to excess heat in the tank. The funny part is that the book I have is 6 years old and was published in 1997 (although he has since updated and republished the book with the same title).
ReefEnabler
Premium Member
You guys should read this:
Feature Article: How Much Light?! Analyses of Selected Shallow Water Invertebrates' Light Requirements
http://www.advancedaquarist.com/2007/3/aafeature1/view?searchterm=too much light
The points of onset photosaturation and photoinhibition are lower for many stony corals than I would have thought. Many SPS they tested have the most photosynthesis around 300-400 PAR. I know I have places in my own tank that are between 700-900 PAR.
This may be why lower MH photoperiods are showing positive results for some. While stony corals certainly seem to be able to tolerate high PAR numbers above 600 or 700, few of them actually perform more photosynthesis at these levels.
I wonder if by having a shorter MH photoperiod, more actual growth is taking place with the supplemental lights, which will be different for everyone. But my 2x80w T5s push between 75-200 PAR into the tank by themselves depending on where you measure. Based on the results in the article its enough for growth.
This article does not go into the effects of super-high light intensities on coloration, other than to speculate that Purple corals can tolerate more light since they reflect more blue and red.
So having the brightest lights on for only 5-6 hours allows the most light demanding stuff (purple sps, tridacnids) to get plenty of light, and then when the intense lights go off, the supplements may allow the real growth to take place for everything else.
Feature Article: How Much Light?! Analyses of Selected Shallow Water Invertebrates' Light Requirements
http://www.advancedaquarist.com/2007/3/aafeature1/view?searchterm=too much light
The points of onset photosaturation and photoinhibition are lower for many stony corals than I would have thought. Many SPS they tested have the most photosynthesis around 300-400 PAR. I know I have places in my own tank that are between 700-900 PAR.
This may be why lower MH photoperiods are showing positive results for some. While stony corals certainly seem to be able to tolerate high PAR numbers above 600 or 700, few of them actually perform more photosynthesis at these levels.
I wonder if by having a shorter MH photoperiod, more actual growth is taking place with the supplemental lights, which will be different for everyone. But my 2x80w T5s push between 75-200 PAR into the tank by themselves depending on where you measure. Based on the results in the article its enough for growth.
This article does not go into the effects of super-high light intensities on coloration, other than to speculate that Purple corals can tolerate more light since they reflect more blue and red.
So having the brightest lights on for only 5-6 hours allows the most light demanding stuff (purple sps, tridacnids) to get plenty of light, and then when the intense lights go off, the supplements may allow the real growth to take place for everything else.
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fred fishstone
Premium Member
I like it!
Reef Stallion
New member
I want more color and growth!
I have just set the ReefKeeper to change my MH from 9 hours a day to 6 hours a day. I am going to leave my T5 Actinics on for 11 Hours. I still want to be able to enjoy the tank. I researched my set up and thought that I would share.
75 gal glass tank that is about 18" deep with a 4' Maristar fixture set 14" off the surface. This fixture contains 2 250watt DE 12K ReefLux MH set in Reef Optix III reflectors that Sanja Joshi rates as probably the top reflector. These are powered by electronic Coralife adjustable Ballasts. Also in the fixture are 2 T5 with Giesemann Actinic Plus.
My plans:
1. reduce photoperiod as above. (Hopefully taking "before" pictures tomorrow and will post)
2. Supplement with Kent Marine's Essential Elements and Coral-Vite
3. Feed the reef with Reef Nutrition's PhytoFeast, RotiFeast and OysterFeast.
4. Order new bulbs for the Maristar. (I'm going with the new ReefLux 20K 250W DE and changing to Giesemann Aquablue Plus T5 bulbs)
I have just set the ReefKeeper to change my MH from 9 hours a day to 6 hours a day. I am going to leave my T5 Actinics on for 11 Hours. I still want to be able to enjoy the tank. I researched my set up and thought that I would share.
75 gal glass tank that is about 18" deep with a 4' Maristar fixture set 14" off the surface. This fixture contains 2 250watt DE 12K ReefLux MH set in Reef Optix III reflectors that Sanja Joshi rates as probably the top reflector. These are powered by electronic Coralife adjustable Ballasts. Also in the fixture are 2 T5 with Giesemann Actinic Plus.
My plans:
1. reduce photoperiod as above. (Hopefully taking "before" pictures tomorrow and will post)
2. Supplement with Kent Marine's Essential Elements and Coral-Vite
3. Feed the reef with Reef Nutrition's PhytoFeast, RotiFeast and OysterFeast.
4. Order new bulbs for the Maristar. (I'm going with the new ReefLux 20K 250W DE and changing to Giesemann Aquablue Plus T5 bulbs)
gaetanocallista
New member
From 8 hours to 6, it's better to diminish slowly?
Reef Stallion
New member
Not 8 hours to 6 hours. 9 hours to 6 hours. I'm still running Actinics for 11 hours as well as my tank does get some natural afternoon sun.
RobbyVonAwesome
New member
Corals only experience skeletal growth at night. Therefore, extending their "night" will give more time each photocycle to grow.
xJake
Active member
My computer is acting up, and I can't get it to read my NEF files (RAW-format photos). I'm working on it as I'm typing this (trying to reinstall the NEF codec), so I should have some "1-week" before and after shots soon of going from 12 hrs. directly to 6 hrs.
As for the "correct" photoperiod, I think it should be varied over time. Faster growth may occur when the photoperiod is shortened, but who is to say that a longer photoperiod doesn't have any effect on coral growth and metabolism as well? I'm going to try changing my photoperiod every few weeks to see if a swing in duration won't have any effect.
Also, I'll be participating in a undergrad research program this summer, and I'm making the proposal to take a further inquiry into this theory using the species M. capricornis and C. curvata. This discussion really has me interested in such a topic, so I'm going to push hard for some kind of experimental design involving this hypothesis. I should have some interesting results to share by this fall.
As for the "correct" photoperiod, I think it should be varied over time. Faster growth may occur when the photoperiod is shortened, but who is to say that a longer photoperiod doesn't have any effect on coral growth and metabolism as well? I'm going to try changing my photoperiod every few weeks to see if a swing in duration won't have any effect.
Also, I'll be participating in a undergrad research program this summer, and I'm making the proposal to take a further inquiry into this theory using the species M. capricornis and C. curvata. This discussion really has me interested in such a topic, so I'm going to push hard for some kind of experimental design involving this hypothesis. I should have some interesting results to share by this fall.
Reef Stallion
New member
Her are my tank photos. This is the best I can do with the cameras I own. I think I need a digital SLR to get better photos.
Reef Stallion
New member
Here are close-ups of some of my corals.
ReefEnabler
Premium Member
your sps definitely look very light to me. hopefully the shorter photoperiod will help but it will probably take several weeks before its noticeable.
what are the rubber bands between your stand doors for??? DIY childproofing???
what are the rubber bands between your stand doors for??? DIY childproofing???
Reef Stallion
New member
My corals definitely were not that light when they were purchased. For example, my blue tort is now green! What?
All this time, I assumed that it was either something in the water or not in the water. All measurements have been excellent though and very stable at that. We shall see if the lighting has been the issue all along.
As far as the rubberbands, they keep the toddlers away. Very wise observation, Grasshopper.
All this time, I assumed that it was either something in the water or not in the water. All measurements have been excellent though and very stable at that. We shall see if the lighting has been the issue all along.
As far as the rubberbands, they keep the toddlers away. Very wise observation, Grasshopper.
ReefEnabler
Premium Member
I'll keep that in mind!
Ive had some corals that have lost color and come back a different color. Had a Poccilopora that used to be bright blue/pink. I didn't have it in enough light and it turned brown. Recently it has green tips. Go figure!
Ive had some corals that have lost color and come back a different color. Had a Poccilopora that used to be bright blue/pink. I didn't have it in enough light and it turned brown. Recently it has green tips. Go figure!
kev apsley
In Memoriam
In my case I had 250w DE 20K over my 24g nano and it turned all my acros a light brown color...even when i had 150w 20K Radium some of the colors were tan and not very good, I chalked it up to nutrients since I don't run a skimmer but I do however do crazy, mad wc's so it didn't make sense?? I cut my initial 8 hr photoperiod back to 4.5 hrs and as I stated earlier, I am seeing colors in some of my sps that I haven't see since the day I acquired them, it's pretty amazing that all this time I was cooking them too much
Reef Stallion
New member
Are you saying that you believe your corals turned brown from extended photo period? I believe that mine turned light. Isn't that odd?
kev apsley
In Memoriam
<a href=showthread.php?s=&postid=14664801#post14664801 target=_blank>Originally posted</a> by Reef Stallion
Are you saying that you believe your corals turned brown from extended photo period? I believe that mine turned light. Isn't that odd?
Yes, they turned a pale (light) brown, after I added more light, prolly too much light in my case. My Aqua Delight which was gorgeous prior to that turned pale brown, cut back photoperiod 2.8 weeks later and colors are returning. I know for a fact it wasn't nutrients because I use a Hanna Colorimeter and my readings are low .002ppm
Reef Stallion
New member
What is a "Hanna Colorimeter?"
ReefEnabler
Premium Member
its a digital phosphate tester... I use the same one and my phos is 0.001
It basically reads subtle changes in turbidity and is very easy to use.
It basically reads subtle changes in turbidity and is very easy to use.
macreefster
New member
for photo-documention heres is mine after two weeks of reducing halides from 10-6 hours, adding actinics 2 hours before and after the halides and recently started dosing vodka and bacteria..... of course i won't really know if its the photo period , vodka dosing or both if i have any improvements, but then i won't care as long as there are improvements!
it would be interesting to see as many before and after pics as possible.
it would be interesting to see as many before and after pics as possible.
