Photo period. (How long is good?)

[E-cubed]

After a 20 years absence, I have a new 10 gallon fairly heavily planted tank. While cycling I had the lights on (26 watts CFL, 5800ºK) for 12 hours. Of course, I got an algae bloom. I learned my ways and reduced my lighting to 8 hours, and I started using Excel Flourish.

The algae is no longer a problem, my tank has been declared as being completely cycled by the tests my LFS did for me, and and the fish I have are happy, but I am not. I want my lights on more so I can enjoy seeing the plants... and fish!

So, I have two questions...

1. How many hours can I keep my lights on and not get an algae bloom?

2. Can I divide those hours and have a dark period in the middle of the day so I can see the tank more in the evening?

Thanks!

 

[Purrbox]

The general guideline is to have the light on for 8-12 hours. Closer to 12 hours if you are growing out your plants and closer to 8 if you are maintaining your scape and/or fighting algae. I tend to run mine for 10 hours and find it to be a nice balance.

You can add a seista to your photo period for extended viewing. Some believe that this also reduces algae, but I've never seen any evidence of it. I prefer to have the light on for a single photo period and just have it set so that it's on the most when I'm around to view them.

 

[neilanh]

I agree with Purr. I run mine for 9-10 hours a day, but I don't let the lights come on until after noon so I can have some viewing time in the evenings when I'm home.

 

[E-cubed]

You always offer good advice Joy. Thank you!

And thank you too Neilan.

 

[SpeedEuphoria]

With 26 watts on my 10G, I found using 10hrs worked well

 

[E-cubed]

I have (today) changed my photo period to 9 hours. I think I will see how that goes and move up to 10 hours as you do next week. Still curious about split photo periods and any real world experiences with them.

Thanks to all!

 

[SpeedEuphoria]

Things take so long to change in lower light levels(patience). IMO its a good idea to leave things for at least 2 weeks(more like a month) to view changes.

So I would try your 9hrs for 1 month, and then see how its going. Then if its OK, add 1/2 hr and wait 2 more weeks, ect.

 

[E-cubed]

Things take so long to change in lower light levels(patience). IMO its a good idea to leave things for at least 2 weeks(more like a month) to view changes.

So I would try your 9hrs for 1 month, and then see how its going. Then if its OK, add 1/2 hr and wait 2 more weeks.

Great advice. Thank you! How about split photo periods?

Earl

 

[SpeedEuphoria]

How about split photo periods?

I'm not sure, havent tried it yet. I'm interested in it. It seems its 50/50, some say it works great for algae control others say why bother.

One thing against it IMO is using flourescent lighting. Flourescent bulbs like to stay on. The ballast puts lots of current through them at startup to get them going, then it drops back to the normal wattage. This effects the bulb life, more startups is harder on the bulbs then hours running. Meaning the bulbs will go bad sooner. So starting them up 2x per day instead of 1, I'm not sure that it will be a direct 50% bulb life decrease but if keeping the same total lights on hours it may very well be close.

That being said most people replace bulbs before they burn out due to spectrum shifting. So I'm guessing that turning them on 2x as much, using the higher current would prob aid in shifting the spectrum sooner also.

This means that for growing plants, the split period/"siesta" prob wears the bulbs out faster.

 

[E-cubed]

I'm not sure, havent tried it yet. I'm interested in it. It seems its 50/50, some say it works great for algae control others say why bother.

One thing against it IMO is using flourescent lighting. Flourescent bulbs like to stay on. The ballast puts lots of current through them at startup to get them going, then it drops back to the normal wattage. This effects the bulb life, more startups is harder on the bulbs then hours running. Meaning the bulbs will go bad sooner. So starting them up 2x per day instead of 1, I'm not sure that it will be a direct 50% bulb life decrease but if keeping the same total lights on hours it may very well be close.

That being said most people replace bulbs before they burn out due to spectrum shifting. So I'm guessing that turning them on 2x as much, using the higher current would prob aid in shifting the spectrum sooner. Meaning that for growing plants it prob wears the bulbs out faster like mentioned above.

I am not too concerned about the bulbs. They cost 99¢ at Lowe's.

 

[newfound77951]

I have my 55g tank with a "siesta". The tank lights come on at 11AM, go off at 2PM, come on again at 5PM and turn off at 11PM. So 9 hours total. I initially had 4 wpg but now have just over 2 wpg on this tank. I initially tried the "siesta" as an algae control method a long time ago and it didn't do anything, but I never bothered to change the settings as once I got my ferts and CO2 under control the tank did very well and I figured why mess with it.

So not terribly scientific but it is a real world experience with the technique. That said, I've had no algae problems in that tank (with DIY CO2!) while my various other planted tanks never seemed to thrive as well. But, lots more variables to consider there.

 

[SpeedEuphoria]

But, lots more variables to consider there.

Yes there are a ton of variables. In hope of turning this into a great thread I will add more info as I see it and encourage other to do so as well.

So far the info below is based on logic, not facts. These benefits are only valid if the split period if plants adapt to the split period and growth is the same as a straight period except for the things mentioned below.


Split photo period/"siesta" Pros/Cons

Pros:
-In a non CO2 injected tank(see note 1) or even DIY CO2 levels may bottom out during the mid day. Then the rest of the day they are struggling to get any/all CO2 that is available. Using the split period with 3-5hours of "siesta" will let the CO2 levels build back up since plants only uptake CO2 when the lights are on. So when the lights come back on they can continue growing at faster rates from the higher CO2 levels. Also the steadier CO2 levels when the lights are on should give plants the upper hand compared to algae that takes advantage of low or fluctuating levels.

-If you have low water movement in the tank, the siesta may also be a benefit as it will let plants and the water time to get more nutrients. If the water surrounding the plants is depleted. This could benefit any tanks that have low flow(even CO2 injected ones), but prob not as much difference in tanks that use substrate ferts.



Cons:
-Fluorescent bulbs wear out faster


Notes:
1:Not all non co2 tanks are the same. NPT(natural planted tanks) or similar that use some kind of "soil" for the substrate are very different from using a regular substrate. The main reason is that in a "soil" tank, the soil and decaying matter can be turned into CO2. So many feel that low water movement in a NPT is good as CO2 levels can get above ambient levels(has been tested in natural bodies of water). In a regular substrate tank, many feel that good surface agitation is good and will try to keep the co2 levels near ambient.


There may very well be a point which is too long for the "siesta", where plants will not adapt very well,so that will have to be considered.

So in a DIY or non CO2 injected tank, my opinion is that for the "siesta" to be used to the most benefit, the 1st lighting period should be even for a DIY CO2 tank, the period inbetween will be found by finding out how long it takes when the lights go out for the CO2 levels to build back up. If it takes to long to build back up, then the last lighting period should be shorter then the 1st.


If its non CO2 injected tank, then the CO2 will prob build up slower when the lights are off depending on the method. So you may need a longer "siesta" to give time for the CO2 levels to rise, it may also not have enough tie to rise to what it 1st was, In this casei ts prob best to have the last lighting period shorter than the 1st.



Please add your $.02

 

[E-cubed]

I have my 55g tank with a "siesta". The tank lights come on at 11AM, go off at 2PM, come on again at 5PM and turn off at 11PM. So 9 hours total. I initially had 4 wpg but now have just over 2 wpg on this tank. I initially tried the "siesta" as an algae control method a long time ago and it didn't do anything, but I never bothered to change the settings as once I got my ferts and CO2 under control the tank did very well and I figured why mess with it.

So not terribly scientific but it is a real world experience with the technique. That said, I've had no algae problems in that tank (with DIY CO2!) while my various other planted tanks never seemed to thrive as well. But, lots more variables to consider there.

That's the kind of example I was hoping for! Thank you.

 

[SpeedEuphoria]

Co2 And Lighting With Siesta Period? - Tropical Fish Forums

all in all, The main reason I see to do it is if it makes it so you can view in the morning then at night(work in between). But I would think if you have a low supply of DIY CO2 then it could help also.

Here is a great thread IMO
http://forum.aquatic-gardeners.org/viewtopic.php?p=3828&sid=3e4e8c5cbc783fd71d348e79818530da

http://www.aquariacentral.com/forums/archive/index.php/t-53703.html

 

[E-cubed]

There are some really good points and opinions here. I hope this thread becomes (and is useful) to the community!

 

[tomherndon]

not sure about this, but a thought I had reading this thread was running two light sets for 4 hours each if one goes with higher end hardware/bulbs. There would be the enormous outlay at the start, but if you set up what you wanted and that rare 'it's just right' occured, running each set once a day for four hours may extend the life significantly? I'm not informed at all about how well specialzed bulbs seal and how much fluorescing gas migrates over time regardless of use. . .