Lights On - How Many Hours

[Tropical_Fish]

How many hours a day should the tank light be on?

I've got a 70L tank which has a 2 foot 18w bulb. I don't have any live plants.

I'm just getting towards the end of my fishless cycle so I haven't had the light on at all yet.

I have a spare mechanical timer (from the xmas tree lights!) which I was going to use to have the light come on at the same time every day.

How long do the fish need? If they need any at all?

The tank doesn't really get any direct sunlight - it's in a bit of a dark corner in the room, obviously it gets lighter and darker in the room with natural light but never gets direct sunlight.

 

[OldMan47]

The fish will be fine with just room light. When you want to see the fish, turn the lights on. Any long period of light in an unplanted tank is an invitation for algae to develop. I run my lights from about 7 to 10 hours, depending on which tank, because the plants need it, but that does not mean that I avoid algae. Algae in a tank with a long daily dose of light is a given that must be dealt with.

 

[VespertineStar]

I have my lights on about 8-9 hours a day cos I loves ta see ma fishies and algae isn't too much of a problem. A quick once over with a mag-float every day keeps the worst of it off. Then take the plants out every 6 months ish if they are looking particularly grubby which coincides nicely with me changing the layout of my tank lol.

That said though there's always someone in our lounge (usually feeding my fish lol) but if, for instance you are out all day and no-one else is there it makes no sense to keep the lights on for that long because as OM47 said the fish do fine with ambient lighting.

 

[Tropical_Fish]

Great stuff, I'll forget about the timer then. I'll switch the light on in the morning when I feed them, then we'll have it on in the evening for a bit.

So the light is just for the humans when there isn't any plant involved!?

 

[OldMan47]

The artificial tank light is so that you can see the fish. The sunlight that comes in to light the room during the day and the overhead lights that you use in the room in the evening are enough for most fish going about their daily lives. The tank lights are for you to watch the fish and to grow the plants.

 

[ChrisChrisChris]

Ooh i didnt realise this, i've now turned my lights off to save electricity as i have no plants currently. The room however isn't very well lit, i can see the fish but its very dim...still ok i suppose?

Wondered if it messed with their "biological clocks" like it would with humans.

 

[drobbyb]

You can also put your lights on a timer, but leave them off for a 2 to 4 hour period a day (usually when you are at work/school) to help control the algae growth. You will still get some algae, but it will be in a lesser amount than if you left them on fot 10 to 12 hours.

 

[H. Houdini]

I've only had a tank set up for six months, and it's been upgraded twice............

...... but I have the lights on all day, (I tend to watch the fish, not TV, which I don't understand in Polish anyway ) as I don't have much work in the summer months, and I have never (and I mean NEVER) had any algae whatsoever.

Guess I'm just lucky!

Harry

 

[Floyds mum]

i have live plants and had a massive problem with algae, i was told to only have the light on while i was there as the fish and plants dont need much light.