2 lighting cycles per day possible?

aquatix02

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Hi everyone,

I have a 90G long planted tank lit with 4 x 30 watt flourescents. The lights currently go on at 7am till about 4pm, in stages. This is approximately 9 hours lighting.

I read in a UK fishkeeping mag where some of the contributors wrote that for his planted tank, he lit it from 8am till 12pm and another cycle at 4pm till 10pm daily. (total 10 hours)

Since I work during the day, I was thinking of doing the same... will it have any adverse affects on the plants or fish if I do that?

My community includes 16 corydoras julli, 7 rummy noses and 4 cherry barbs.

Thanks in advance guys!
 
Some plantkeepers have advocated using a "siesta" as an algae control method, two lighting cycles with a short break in the middle. Try searching for "siesta" and "aquatic plants" and you should be able to find a full run down of how it'll effect your plants.

It seems to me that most reports were that it didn't really work as an algae control method, partly because the algae could start and stop faster than the more complex plants. Plants need a certain amount of time to start photosynthesizing at full speed and need to rest after a certain amount of time. Too long of a photoperiod doesn't help the plants and will encourage algae. Too short of a photoperiod may do the same, or it may not -- this question would do better in the Plants forum.
 
I agree, and will move it over.

I favor one light period for my tank, but it doesn't have to be during the outdoor lighted frame. My lights don't come on until around 11, then go off around 9. The ambient light of the morning provides a good time frame for the fish that don't like as much light but are not fully nocturnal, and the afternoon light is for the plants, and my viewing in the evening.
 
Plants(and algae) do fine with 10-12hrs/day. There's no need to do 2 cycles in the first place. Algae issues should be address by other means or a complete blackout for 3-5 days.
You can try it out, but there's not any real advantage. You can set your light time for later if you want to see it in the evening etc.

Regards,
Tom Barr
 
Here's another possibility. I have 10 hours/day of full strength light (55W 5500K PC on 25 tall), with 2 hours at either end with 13W 3500K dawn/dusk. Allows me to go to work and gym and still get to see everybody, without causing an algae bloom. The plants seem quite happy with it, and the loaches are so much happier to come out and play when the lights are dimmer. Could you just have one of your 30W on for a couple of hours at either end of the day, or just add a little dawn/dusk light?
 
Just to clarify, I offered it "siesta" mostly as a search term. I know that its been tried and my recollection is that it wasn't terribly successful and that it might just give the algae an edge if anything.

Like OG, I use a single photoperiod that doesn't line up with my local timezone. The tank is in a west facing room that never gets huge ambient light and not much at all in the morning. The fish generally stay in their hanging-in-the-water sleep mode. Lights come on at 11am (after a half hour with the little red twilight) and go off at 10pm (followed by 2 hours with the little red twilight).

When in doubt, follow Tom's advice :p (although OG is usually on the money and this new feller seems pretty sharp as well).
 
My old tank had about 45 minutes in the morning and then came back on from noon until 10:00.

Mind you this was not a spectacular planted tank. It was well established for about 5 years, but was not what I'd call a thriving tank. Nothing grew....but nothing died either. It had some bba on the driftwood/java fern and glass at the back, but even that didn't really thrive.
 
Thanks for the replies. I've decided to just light my tank from 4pm till 12pm so that i can view the tank at night... i hope indirect sunlight from my windows won't bother the fish!

I have one red-light that comes on before and after the lighting period to minimise the sudden lighting shock... its actually a pink plant gro-type... should simulate dusk effectively. i actually plan to have 2 plant-gro since my flourescent ballast does not allow individual lighting control and at the moment, the gro-light is coming on with a white one.

I actually reckon its not that natural to have the light 'siesta' everyday since in nature, there are no daily storms throughout the whole year... so pending further research, i think i'll stick with single period lighting for now..
 
Well, actually, Florida has daily rainstorms, as do many other tropical locales, but you're right in saying that these don't occur year-round...just during the rainy season.

Your idea for a set-up sounds good, and you're going above and beyond what most of us do with the dusk/dawn lights (but continue using them...that's a great idea!)
 
Even with cloud cover here, the light intensity is far higher than most anyone's tank. The duration increases during the summer resulting in more plant growth even if cloud cover increases.

Most lake/pond/ditch aquatic systems photosyntheize well for the first few hours of the day. After most of the CO2 is gone, they slow down.

If you look at the Pacific Ocean's productivity, algae do better outside the equator on both sides, but algae there are not limited by carbon or depth........

Regards,
Tom Barr
 
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