How Long For?

[SJ2K]

Exactly how long is it recommended for our aquarium lights to be left on? My tank consists of no real plants and I leave my lights on for 12 hours a day.

Any real clarity would be great here, ive heard a few different ideas!

 

[Davo86]

without plants - 8 hours

 

[SJ2K]

And why? (Not doubting you, just need reasonings to make a good judgement).

 

[Davo86]

well a contributing factor to algae growth is usually too much light. Reducing the lighting time to eight hours, or a bit less if necessary, will help reduce this algae growth to a level that is easily controlled

 

[fry_lover]

if you dont have plants then aqaurium lights "need" to be on for ZERO hours per day

unless the room is virtually pitch black

Aquarium lights are for either the plants benefit or our benefit and not actually the fish

EDIT: in terms of your preference, i would say have them on for whatever length you want within reason, as long as it doesnt cause algae as mentioned

In my tanks that dont have plants, i generally have the lights on between 7pm and mid-night, which is only 5 hrs

 

[Davo86]

ok fair point, but the question was how long is recommended not how long is needed, The light obviously gives a more attractive look to any aquarium and so many people would simply leave this on for as many hours as they are up and in some cases even longer, 8 hours gives people enough time during the day to admire the tank without having a consequence of a algae bloom that you can't control

 

[SJ2K]

Lol, well I already have a brown algae issue. I like the lights on as its really dark without (black gravel and background = struggle to view fish)...I might see if I can set my timers so theres a break mid-day.

 

[paul_219]

I keep mine for 8 hours.

 

[backtotropical]

From what i understand, algae (especially brown algae) can be triggered by too little light as well as too much light.

I'd say no light at all, or a minimum of 8hrs, and no more than 12.

 

[raptorrex]

mine are timed for 12 hours, roughly the daylight hours for summer in the tropical region. not based on any science, just my reason for that figure. light time may have an effect if you are trying to breed. i dont breed fish, but if i try to breed cray, the best is to give 14 hours. it may be the same for some fish!