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lorenz0
03-06-2009, 06:01 AM
came across this thread tonight and found it extremely interesting. I am going to change my lighting to shorter periods with my growing bulbs while staying the same with my supplimentals.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1582958&perpage=25&pagenumber=1

Trigger Man
03-06-2009, 06:12 AM
And here I just rose my lighting period from 9 to 10 hours after seeing Lobsterboys tank and hearing how long others keep their lights on. Right now I've noticed more growth, so maybe the lighting period has to be varied here and there, just like how it happens in nature with seasons.

lorenz0
03-06-2009, 06:21 AM
From what i have noticed in my tank I actually had to bring my schedual down once from 10-9 hours and i have noticed improvement. Today i was thinking how my T5's are producing to much light and in some cases I have also noticed that even milli's in the higher points in my tank are losing color and a stylo on the sand is losing it's base color. My acro's are doing decent but have become a bit dull so right now i am going to give this a shot. i will be updating my build thread so i will have before and after shots.

GreenSpottedPuffer
03-06-2009, 06:32 AM
I brought mine down from 10 hours to 6 hours a few months back. I have seen nothing but great results. Pretty much exactly what people have been saying in that thread--better polyp extension, better color, better growth.

It makes sense too...If you go a bit further than that thread and do some reading (search on google scholar about Photoinhibition in corals) you will find its not completely clear yet but most scientists are leaning towards excessive amounts of light actually "exhausting" corals and slowing growth down.

hockey nut
03-06-2009, 07:38 AM
7 hours for my tank. Good growth and nice colours. So far so good. :)

GreenSpottedPuffer
03-06-2009, 07:44 AM
7 hours for my tank. Good growth and nice colours. So far so good. :)

How long have you been at 7 hours?

TheRealBigAL
03-06-2009, 08:21 AM
came across this thread tonight and found it extremely interesting. I am going to change my lighting to shorter periods with my growing bulbs while staying the same with my supplimentals.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1582958&perpage=25&pagenumber=1

Great link ! Thanks. I am now going to be changing my lighting schedule :lol:

ColinD
03-06-2009, 12:37 PM
saw the same post on reef central last week, and after a week of 5 hour photo periods I've definitely seen a difference, much more polyp extension and all my SPS are colouring up quite nicely. I don't really need the lights on when I'm at work anyways and evaporation has been quite a bit less as well.

Colin

fishytime
03-06-2009, 12:47 PM
From what i have noticed in my tank I actually had to bring my schedual down once from 10-9 hours and i have noticed improvement. Today i was thinking how my T5's are producing to much light and in some cases I have also noticed that even milli's in the higher points in my tank are losing color and a stylo on the sand is losing it's base color. My acro's are doing decent but have become a bit dull so right now i am going to give this a shot. i will be updating my build thread so i will have before and after shots.

Ok trying really hard not to come off sounding harsh but, your tank is basically brand spankin new. I would venture to guess that is why you are losing color in some of your acros....and as far as the stylo goes....I warned you about them, did I not?

lorenz0
03-06-2009, 01:37 PM
lol on my wicked frag order we needed an extra $25 to get half off for shipping so i paid it and told dave to suprise me and thats what he sent me. Its actually doing good and its been 2 weeks, just lost a bit of color. I test my water every second day, lose of color for sure is due to the light. I moved the stylo higher in the tank for a day and the light basically cooked it, its back down in the lower part of the tank and color has come back.

Black Phantom
03-06-2009, 02:14 PM
It's interesting. We put very high intensity bulbs over our tanks and then we turn off the lights:lol:
I have my 50 gal with just one 14000k 150MH over it. There's lots of light for my SPS and I can run my lights all day. That way I can actually enjoy "seeing" my fish and corals:biggrin:

Aquattro
03-06-2009, 02:16 PM
My current tank runs at 6 hours, better results than I've ever had, color-wise. Growth is not a concern, I actually prefer less growth.

Aquattro
03-06-2009, 02:18 PM
, so maybe the lighting period has to be varied here and there, just like how it happens in nature with seasons.

The photoperiod over the areas corals come from really doesn't change at all over the year. It gets dark in Bali around 6ish every day.

mark
03-06-2009, 03:13 PM
interesting link, less is more

Koresample
03-06-2009, 05:17 PM
For me i had too many variables, i switched from a 2 bulb 10k and actinic, to a 4 bulb 420/460 and 700+ lights, different fixture and programming. I was running 12hrs on and 12 off, now the auto programming on the aquaticlife fixture runs the 420/460 from 8am to 8pm, the 700+ from 10am to 5pm and the moonlights from 8pm to 11:30 pm. I have notice a large increase in my coral algae growth, almost no nuisance algae at all and all my corals are getting more colourful. Like i said though, too many variables as i also switched to RO water, started testing/optimizing chemistry, added a refugium...on and on and on. If everything is equal, then the lights could be the reason, but too many other things have also changed. when i started my tank i started a journal and keep track of all my water changes, dates of testing and results, even when a fish dies. This is the only way imho that you can say one thing or another really had an effect.

fishytime
03-07-2009, 12:00 AM
Really think you have your issue misdiagnosed. Just my opinion though.

GreenSpottedPuffer
03-07-2009, 12:39 AM
Really think you have your issue misdiagnosed. Just my opinion though.

Who misdiagnosed what issue?

digital-audiophile
03-07-2009, 01:12 AM
:biggrin: I think Doug's been drinking too much coral snow ;) LOL

karazy
03-07-2009, 02:36 AM
:biggrin: I think Doug's been drinking too much coral snow ;) LOL

All his wrasses were swimming really fast and the colors made him a lil loopy :lol:

lorenz0
03-07-2009, 03:00 AM
Who misdiagnosed what issue?

he thinks i mis-diagnosed my issue. this wasn't an issue though, common fact. For instance, one of the new milli's i picked up off of snappy turned white on the side facing the light, but the side that isn't still looks great. also i have found that stylo and birds nests are great indicator corals when it comes to to much light. the only birds nest that can actually withstand the higher light is the pink one while bith my other types and the stylo start to lose base color and bleach out.

but this thread was suppost to be a helpful link, not an issue i am facing

GreenSpottedPuffer
03-07-2009, 04:26 AM
:biggrin: I think Doug's been drinking too much coral snow ;) LOL

Who is Doug?

Man...I am getting really confused now.

GreenSpottedPuffer
03-07-2009, 04:28 AM
he thinks i mis-diagnosed my issue. this wasn't an issue though, common fact. For instance, one of the new milli's i picked up off of snappy turned white on the side facing the light, but the side that isn't still looks great. also i have found that stylo and birds nests are great indicator corals when it comes to to much light. the only birds nest that can actually withstand the higher light is the pink one while bith my other types and the stylo start to lose base color and bleach out.

but this thread was suppost to be a helpful link, not an issue i am facing

Oh ok...I guess I figured out who Doug is then.

Sounds like you have the "diagnosis" right then. I too have lost corals to bleaching from too much light too quickly. I agree about the birdsnest too--have to be careful about how much light they get. Even my hot pink birdsnest turns pale in high light. Once I moved it to lower light, it colored back up.

Trigger Man
03-07-2009, 04:28 AM
doug is fishytime.

fishytime
03-07-2009, 01:47 PM
Dude....your tank is less than two months old....period. Ask others here how old they feel a tank should be before it can sustain sps? I have the exact same light you have and the depths of our tanks are similar. Your acros are not losing color because of the light. Your tank simply isnt ready for some of the more sensitive sps. Hence the reason I recommended montis or birdsnest if you wanted to try putting some sps into a tank that young.

Myka
03-07-2009, 02:36 PM
Dude....your tank is less than two months old....period. Ask others here how old they feel a tank should be before it can sustain sps? I have the exact same light you have and the depths of our tanks are similar. Your acros are not losing color because of the light. Your tank simply isnt ready for some of the more sensitive sps. Hence the reason I recommended montis or birdsnest if you wanted to try putting some sps into a tank that young.

Why don't you start a new thread about this issue? Or maybe PM him? Just because someone doesn't do something the way you suggest, doesn't mean it gives you the right to harass that person. Not all newbies are willing to take advice...they're already experts, dontcha know? ;)

On the subject...I find this awfully interesting. I would also be really interested to find out if there is a "perfect" PAR/PPFD for individual corals. I bet there is.

lorenz0
03-07-2009, 02:43 PM
lol but i am not complaining about major lose of color. My green tabling acro got slightly lighter, but in turn my pink birds nest actually became pink. before it was like a dull purple with blue polyps and now its actually pink. But when i am talking about the light being to intense for certain corals its true. at first i set the stylo higher in the tank and the base orange started to go white, so i moved it back down to the sand and the base color came back. now after 1 day of cutting down the lighting the stylo and the green polyp birdnests are starting to gain color again (the birdsnest bleached out during shipping). I know my tank is young but i haven't lost any colonies, just had some issues with smaller frags. no biggy. but this thread isn't about me, more about an informative link talking about photo periods.

Myka
03-07-2009, 03:06 PM
but this thread isn't about me, more about an informative link talking about photo periods.

Exactly, so why don't you two go make a thread that you can scrap it out instead of using this one? This thread is an interesting topic.

Mods? Would be nice if you could clean this thread up please. :)




I wonder also how effective this cutback photoperiod would be for people who don't have supplimental lighting, or lack the ability to turn certain bulbs on an off independently. Like, say my 33g tank which has 2 T5s which are on for 11 hours a day (I think lol). Seeing as they aren't overly intense, I'm wondering if a cutback photoperiod would be beneficial or detrimental. I'm looking to add a MH to the setup, so eventually it will be a moot point for me, but in the case of others whose lighting isn't overly intense, I wonder if a longer photo period would be more or less beneficial. The same that I wonder if a tank with 250w halides would need a longer photo period than that same tank with 400w halides over it? So, in simple terms without all this thinking out loud (lol), does PAR/PPFD play into the equation?

Aquattro
03-07-2009, 03:08 PM
Yes, let's keep on topic please.

fishytime
03-07-2009, 03:10 PM
Why don't you start a new thread about this issue? Or maybe PM him? Just because someone doesn't do something the way you suggest, doesn't mean it gives you the right to harass that person. Not all newbies are willing to take advice...they're already experts, dontcha know? ;)

.

I am not at all harassing Laurier (we know each other outside the forum). Is this not the reason why we post here? To gain insight and benefit from others experience(s)? I am just saying that he is making changes to the way he is running his system based on the fact that he feels the light is too intense for his sps.( 6x39w HOT5s???). I am just trying to make the point that his system is very young and this fact is more likely the cause of some of his sps loosing color.

Reducing the lighting cycle will darken the colors of sps. The coral reacts to the lack of light by darkening itself in an attempt to absorb as much of the available light as it can. Much like the difference between wearing a black shirt or a white shirt in the summertime(mmmmm summer).

marie
03-07-2009, 03:25 PM
I have 3 250w MHs on for 10 hrs a day, no other supplemental lighting.

I like seeing my fish so I don't see me cutting back on the photoperiod anytime soon :mrgreen:

Oscar
03-07-2009, 03:31 PM
so maybe the lighting period has to be varied here and there, just like how it happens in nature with seasons.

Yes, very interesting discussion. The photo period for corals, since most are found very close to the equator should be relatively constant through the year, not seasonal.

But...what will vary is intensity from day to day to account for cloud free, cloudy and rainy days.

Currently I have been running actinic 12 hours, hallide 10 hours, moonlights, 4 hours. Some of my corals seem to be losing a bit of colour.

So here is what I am thinking of shifting to in my photoperiod:

Actinincs: 9.5 hrs per day
Moons: 4 hrs per day
Hallide: Sat/Sun: 7.5 hrs
Monday: 5.5 hours
Tuesday: 3.5 hours
Wed: 0 hours
Thursday: 3.5 hours
Friday: 5.5 hours

The additional benefits are less chance for the tank to overheat, less evaporation and fewer algae issues.

Thoughts?

Doug
03-07-2009, 03:32 PM
Who is Doug?

Man...I am getting really confused now.



:noidea:

Myka
03-07-2009, 03:34 PM
LOL Doug!!!

Oscar, that's a whole lotta pain in the butt, but if you have the time for it, or some sort of controller that will do that for you, I would be interested to see the results. However, I doubt it would make any more difference than just lowering the photo period to a steady number.

GreenSpottedPuffer
03-07-2009, 03:34 PM
Exactly, so why don't you two go make a thread that you can scrap it out instead of using this one? This thread is an interesting topic.

Mods? Would be nice if you could clean this thread up please. :)




I wonder also how effective this cutback photoperiod would be for people who don't have supplimental lighting, or lack the ability to turn certain bulbs on an off independently. Like, say my 33g tank which has 2 T5s which are on for 11 hours a day (I think lol). Seeing as they aren't overly intense, I'm wondering if a cutback photoperiod would be beneficial or detrimental. I'm looking to add a MH to the setup, so eventually it will be a moot point for me, but in the case of others whose lighting isn't overly intense, I wonder if a longer photo period would be more or less beneficial. The same that I wonder if a tank with 250w halides would need a longer photo period than that same tank with 400w halides over it? So, in simple terms without all this thinking out loud (lol), does PAR/PPFD play into the equation?

My tank actually has no supplemental lighting. So its literally both 400 watt 20K MH come on at 3PM and both are off at 9PM. I would say PPFD does come into play for sure. My PPFD is actually quite low though based on Sanjays testing.

For me, its working out so well right now, I can't imagine changing. I see my corals and fish all day long, 6 hours under bright light and about 12 hours under room light (my room is very open and bright most days). My power bill is down, no algae or cyano anymore, corals look better than ever. Can't complain.

GreenSpottedPuffer
03-07-2009, 03:36 PM
:noidea:

Oh yeah...

:laluot_23:

Doug
03-07-2009, 03:37 PM
Exactly, so why don't you two go make a thread that you can scrap it out instead of using this one? This thread is an interesting topic.

Mods? Would be nice if you could clean this thread up please. :)




I wonder also how effective this cutback photoperiod would be for people who don't have supplimental lighting, or lack the ability to turn certain bulbs on an off independently. Like, say my 33g tank which has 2 T5s which are on for 11 hours a day (I think lol). Seeing as they aren't overly intense, I'm wondering if a cutback photoperiod would be beneficial or detrimental. I'm looking to add a MH to the setup, so eventually it will be a moot point for me, but in the case of others whose lighting isn't overly intense, I wonder if a longer photo period would be more or less beneficial. The same that I wonder if a tank with 250w halides would need a longer photo period than that same tank with 400w halides over it? So, in simple terms without all this thinking out loud (lol), does PAR/PPFD play into the equation?


Good point on the supplement lighting
I remember someone preaching it on RC, then find out he ran 4 110w vho lights, besides his 250w halides.

I run mine for 10hrs. and my useless actinics for 12. However I only have a single 150w. I may cut it back a bit and see, esp; after I start UltraLith.

GreenSpottedPuffer
03-07-2009, 03:39 PM
I am not at all harassing Laurier (we know each other outside the forum). Is this not the reason why we post here? To gain insight and benefit from others experience(s)? I am just saying that he is making changes to the way he is running his system based on the fact that he feels the light is too intense for his sps.( 6x39w HOT5s???). I am just trying to make the point that his system is very young and this fact is more likely the cause of some of his sps loosing color.

Reducing the lighting cycle will darken the colors of sps. The coral reacts to the lack of light by darkening itself in an attempt to absorb as much of the available light as it can. Much like the difference between wearing a black shirt or a white shirt in the summertime(mmmmm summer).

You need to do some reading my friend...

People are finding corals coloring up, not darkening at all. They have been actually looking for the ideal photo period based on photoinhibition. This will allow the corals to have to work a lot LESS and have more time to grow/color up. Much like when you go to the gym, you are not building muscle while lifting but afterwards while your muscles are being repaired. You can really overdo it by staying in the gym too long. Corals can also get very tired under long periods of light. They actually then can darken. Since corals store energy during the day and grow at night plus can only utilize a certain amount of light to begin with, long photoperiods, especially in our tank (which are stuck at high noon) are unnecessary and sometimes harmful. Not harmful in the sense that you are going to kill corals but harmful in the sense that you can slow down growth and coloration. Although to some thats not a bad thing...

Certainly some coral may darken under lesser photoperiods but to claim they WILL darken as you have is kind of a broad statement. Perhaps look at the results on RC for a short photoperiod. You may want to start with the TOTM from a few months back.

http://reefkeeping.com/issues/2009-01/totm/index.php


Looks incredible to me...Not too dark at all.

Oscar
03-07-2009, 03:39 PM
LOL Doug!!!

However, I doubt it would make any more difference than just lowering the photo period to a steady number.

We'll see. If it reduces the algae situation, and the amount of evaporation then that is worth the time.

Myka
03-07-2009, 03:40 PM
My tank actually has no supplemental lighting. So its literally both 400 watt 20K MH come on at 3PM and both are off at 9PM. I would say PPFD does come into play for sure. My PPFD is actually quite low though based on Sanjays testing.

For me, its working out so well right now, I can't imagine changing. I see my corals and fish all day long, 6 hours under bright light and about 12 hours under room light (my room is very open and bright most days). My power bills down, no algae or cyano anymore, corals look better than ever. Can't complain.

Ya, 20K really reduces PAR. Just wondering...why wouldn't you use some supplimental actinics, and change to a lower Kelvin on your halides? I would think you would get better growth just based on that as coral growth is increased with lower Kelvin due to photosynthesis increaasing.

For you guys saying you want to see your fish...do you guys stay home all day? Pfff...I don't like you guys anymore. Wish I could do that! Heck, I haven't even seen my home since December...oh wait, I don't even have a home anymore. :lol:

GreenSpottedPuffer
03-07-2009, 03:54 PM
Ya, 20K really reduces PAR. Just wondering...why wouldn't you use some supplimental actinics, and change to a lower Kelvin on your halides? I would think you would get better growth just based on that as coral growth is increased with lower Kelvin due to photosynthesis increaasing.

For you guys saying you want to see your fish...do you guys stay home all day? Pfff...I don't like you guys anymore. Wish I could do that! Heck, I haven't even seen my home since December...oh wait, I don't even have a home anymore. :lol:

Because the goal of my new tank was to use as little equipment as possible and I am super happy with growth as of now. As for major equipment, I have the two halides, skimmer, controller and ZEO reactor. I also have no canopy to put other lights in. Trying to keep the real sleek and clean look.

I may go back to 14K next bulb change but I doubt it.

More growth in my case is not what I am looking for anyways, its an added bonus. I am after color.

mark
03-07-2009, 06:16 PM
What we need is some PAR measurements on a reef in Bali say logged hourly for a year, imported in to controller hooked up to a set of calibrated Sfiligoi dimmable MH lights.

Madreefer
03-07-2009, 06:46 PM
This may be a stupid question, but should there be a time of total darkness? When my actinics and MH are off my moonrays are on which gives my tank light 24/7

Oscar
03-07-2009, 08:00 PM
but should there be a time of total darkness?

Would the ocean be exposed to light 24/7? Probably not. A full moon only appears once every 28 days and even then you would have to expect some clouds to block some moonshine.

lorenz0
03-07-2009, 08:29 PM
I am not at all harassing Laurier (we know each other outside the forum). Is this not the reason why we post here? To gain insight and benefit from others experience(s)? I am just saying that he is making changes to the way he is running his system based on the fact that he feels the light is too intense for his sps.( 6x39w HOT5s???). I am just trying to make the point that his system is very young and this fact is more likely the cause of some of his sps loosing color.

Reducing the lighting cycle will darken the colors of sps. The coral reacts to the lack of light by darkening itself in an attempt to absorb as much of the available light as it can. Much like the difference between wearing a black shirt or a white shirt in the summertime(mmmmm summer).

ya i know its young, and your more than welcome to come over and take a peak. after only a day and a bit I have noticed a big change in polyp extension in my tank. I purchased this branching sps last week and it has made the biggest change out of all the other ones in my tank. when it was at red coral polyps were fully out all the time. when i brought it home polyps haven't had the greatest extension like how it was at the store till now.

I will have to bump this thread in a month with updates. So far its working great

marie
03-07-2009, 10:00 PM
.... after only a day and a bit I have noticed a big change in polyp extension in my tank...

To play devils advocate, better polyp extension is not always necessarily a good thing. It could be a sign that the corals are starving :biggrin:

Reefer Rob
03-07-2009, 11:50 PM
Don't you find that when you have more polyp extention it happens at a time when your corals are growing well and have their best color? When the polyps are retracted on a coral in my tank it's always when it's not happy.

marie
03-08-2009, 03:39 AM
Don't you find that when you have more polyp extention it happens at a time when your corals are growing well and have their best color? When the polyps are retracted on a coral in my tank it's always when it's not happy.

Polyps on an sps coral are there to catch food, usually there is more food in the water at night which is why you get better night time extension. If a coral is hungry and/or if there is food in the water it extends polyps to maximize food catching potential.
A coral that wants to eat is healthy, a coral that needs to eat because it's not getting enough food from photosynthesizing is not

Reefer Rob
03-08-2009, 04:00 AM
I was trying to simplify things.

Forget all the theories about what a coral needs or wants. Nobody really seems to know anyway... at least it's been debated to death.

I'm talking about when you're sitting in front of your tank, and you say to yourself "man, everything is looking sooo good now!" Your corals are growing like weeds, and the color hurts your eyes.

fuzzy sticks are healthy sticks... No?

marie
03-08-2009, 04:03 AM
Well I did say I was playing devils advocate and showing better polyp extension just because you have drastically cut back your photo period is not necessarily a sign of health

lorenz0
03-08-2009, 06:36 AM
so true marie and i agree. its wierd though, some will have great polyp extension and others won't during the day. right now i am super interested how this turns out.

GreenSpottedPuffer
03-08-2009, 07:55 AM
Well I did say I was playing devils advocate and showing better polyp extension just because you have drastically cut back your photo period is not necessarily a sign of health

I agree and if that was the only "good" sign, I for one would never have cut back my photoperiod. But there is much more to it than good polyp extension.


I don't think anyone is arguing that this is the way to go or even the best way to light a tank. Its just yet another way that is working well for many. I know people with their halides on for 12 hours and by looking at the results (corals), you can't argue that they are wrong. Same way you can't say that TOTM I linked is not working out with his 6 hour photoperiod.

Delphinus
03-08-2009, 08:14 AM
I'd love to see a chart of a PAR or lux reading taking on an hourly basis on a reef somewhere in the tropics just to see what the intensity curve really looks like.

Last time I checked the tropics were an even-Steven 12 hour day. To my Calgary eyes the intensity is all the same except for sun-up and sun-down. But the flip side is what is the difference between one million dollars and two million dollars? To a guy who has neither, they are both "wow that's a lot of money." But to someone else it may make a large difference. So that's why I say I'd love to see what a real reef encounters typically. Hey I'm all for a 6 hour halide day because I pay way too dang much for electricity per month and I need to find a way to reduce that .. but I want to be able to see my fish. I'm thinking maybe some supplemental T5's just to frame the actual intensity portion of the day.

Starting to hear enough anecdotal evidence to believe that the reduced photoperiod is onto something but on the flip side I wonder if people are a little too eager to jump on the conclusion bandwagon. Sorry, not trying to be harsh but the fad bandwagon can really be a little bit silly in this hobby at times .. :)

GreenSpottedPuffer
03-08-2009, 08:56 AM
I'd love to see a chart of a PAR or lux reading taking on an hourly basis on a reef somewhere in the tropics just to see what the intensity curve really looks like.

Last time I checked the tropics were an even-Steven 12 hour day. To my Calgary eyes the intensity is all the same except for sun-up and sun-down. But the flip side is what is the difference between one million dollars and two million dollars? To a guy who has neither, they are both "wow that's a lot of money." But to someone else it may make a large difference. So that's why I say I'd love to see what a real reef encounters typically. Hey I'm all for a 6 hour halide day because I pay way too dang much for electricity per month and I need to find a way to reduce that .. but I want to be able to see my fish. I'm thinking maybe some supplemental T5's just to frame the actual intensity portion of the day.

Starting to hear enough anecdotal evidence to believe that the reduced photoperiod is onto something but on the flip side I wonder if people are a little too eager to jump on the conclusion bandwagon. Sorry, not trying to be harsh but the fad bandwagon can really be a little bit silly in this hobby at times .. :)

I don't know...for me the results people are getting are more valuable than any PAR reading really. IMO too many variables. For one, the sun over a reef in the tropics does not stay stuck at a high noon position for 12 hours like our lights do.

EDIT: Missed that you mentioned an hourly reading. This would be nice to see actually.

Again, I think it just all comes down to whats working for your tank. I have seen nothing but improvements after shortening the photoperiod. Perhaps the improvements in coral coloration and growth are a result of some other change or just an overall more stable system but I do know for sure that the improvement in my electric bill is the direct result of the lessened photoperiod--this is enough for me.

I say don't change whats working for you. If you are having great results at 10 hours, stay there. If you aren't liking the tank and want to try something new, try shortening the photoperiod. Nothing to loose really. Lots to gain if it works for your tank. My 6 hours a day bulbs will last much longer now than when I was running them 9-10 hours a day.