Light cycles

[earhtmother]

I know fish need a day/night lighting cycle but does it have to be actual day/night or is a light/dark period sufficient?
My issue is here in Ontario we have a *time of use* system in place for electricity costs which means that the day is divided into 3 rate periods which change on a winter(Nov1-Apr30)/summer(May1-Oct31) cycle. Right now its
On Peak 7am-11am & 5pm-7pm $0.132 kWh
Mid Peak 11am-5pm $0.095 kWh
Off Peak 7pm-7am $0.065 kWh
I can't control the power the filters & heaters use but the lights are completely under my control. Tanks are in the basement with one window that let's in a semi decent amount of light on a sunny day between 10am & 5pm(I don't need to turn lights on to do basic tasks) it's dark by 5pm. At the moment the tank lights are on from 9:30pm-7am approximately. So they are getting 3 hours semi darkness 7am-10am, 6 hours of twilight 10am-5pm, 5 hours of night 5pm-9:30pm then 9 hours of daylight. Not exactly a proper day/night scenario but what I would prefer to keep if it isn't bad for their health. Of course this will all change in 4 mths but that's a problem for another day.
So opinions everyone?

 

[BBradbury]

Hello mother...

You don't need to overthink the lighting for your fish. Most fish we keep are tropical and used to long hours of daylight. If you keep your tank lights on a timer set for 12 hours on and 12 off, the fish will be fine. They don't require total darkness, just a 10 to 12 hour period of shadowy or dim light. What some refer to as dusk.

B

 

[earhtmother]

No timer - I just turn the lights on when I vet home from work and off when I wake up

 

[Fresh2o]

No timer - I just turn the lights on when I vet home from work and off when I wake up

You can still put those on a timer and keep the schedule you are currently using.
If you are using LED fixtures, then the wattage should be very low.