Split photo periods?

[prdad]

So I need to cut back the lighting on my tank. We're out from 8 till 5 so it would be nice if we could have the tank lit for breakfast and tea times. The tanks in the kitchen btw.

Is there a problem lighting for 3 hours in the morning and 4 in the evening? I suppose it's only like cloudy days in nature...

 

[Nathaniel Whiteside]

You'll have algae problems I your injecting co2

 

[foxfish]

Split lighting has been & is still, a popular method for some folk but the rest period is usually one hour.

 

[geoffbark]

Nothing wrong with split lighting. But there are other ways to reduce lighting. You could use floating plants or remove reflectors or lift light higher above tank.

You could also maybe use a small led light for the morning swapping to you main bright light for the afternoon on timers.

What ever works best for you.

 

[foxfish]

That is interesting Geoff..so he can have 3 hours then 8 hour rest then 4 hours & it will be fine?
I cant say I have ever tried that so I dont actually know?

 

[Antipofish]

The other question to ask, is "Is it natural to have a long rest between photoperiods in terms of fish"? It would confuse the heck out of them. Would you like it if it went dark TWICE a day

 

[prdad]

Well I live in Manchester and if it's not raining and a bit dark then something's not right. There's ambient light in the kitchen during the off period and I've observed the fish and they seem active so they must think the suns clouded over. Although I'm not a fish mind reader.

Antipofish I've not forgotten about your tank lid, it's just been very busy at work, mustnt grumble etc etc

 

[Barbapappa]

I just started up my tank and red about this principle quite a bit.

To prevent algae issues I use 3 hours on, 3 hours off and then another 3 hours on. Whilst reading about it I found that 3 hours on is the advised minimum because you give the plants the opportunity to start up and to really get going. The 3 hours break will give the co2 levels in the tank the chance to stabilize in order to be at the appropriate level for the last 3 hours of light. My idea is to expand these 3 hour blocks to 4 hours further down the road.

About the fish, I don't have any in yet, but I cannot imagine them caring very much. In "the wild" I imagine there to be places where, because for example a big tree standing in front of a pool, the sunlight hits the pool intensely for a few hours, then hits the tree for a few hours causing the light to dramatically decrease and then hit the pool again. Giving roughly the same effect as I am doing with my tank.

I don't use pressurized co2 btw.

 

[sanj]

You can have split photo periods, but I am not sure that the photo periods you are suggesting are long enough. I use pretty short photoperiods 6-7 hours on different tanks, but it appears you are suggesting shorter than this and pretty long rest period in between.

Try it, there is only one way to find out, but im thinking on the lines of the plants having enough time to utilise the light, make energy and grow.

 

[clonitza]

There are a bunch of myths about lighting, there's no minimum or maximum required period, you can use any as long as you do the fertilization correctly and choose the right plants. Be advised that for longer periods (>12h) you need to cut the intensity a lot and provide shades to keep the fish stress levels low.

This is one of my tanks running a 2h-3h(p)-2h-3h(p)-2h photo period for the last 2 years, CO2 via liquid carbon.