Circadian lighting--could this work?

[Chi-Chi]

I originally posted this in another forum, but I quickly realized this would probably be the better site for this idea (given some of the incredible setups I've seen).

For larger tanks with lighting coming from suspended fixtures over glass tops (or no tops), why not try to mimic the natural progression of the sun in the sky? You could have 3-6 different fixtures, hanging perpendicular to the front and back of the aquarium, assigned to timers that clicked them on incrementally from east to west. They could be spaced out by three hours or so, with a little overlap. The first and last bulbs could be somewhat dimmer then the "mid-day" bulbs in the middle of the arrangement.

I feel like this could help induce a more natural circadian cycle for the different species, and would probably help most during breeding. It might reduce algae as well, as the shifting shadows would make certain areas of the tank receive less light at various times of the day. Also, these shadows would perhaps make the aquarium look more naturalistic.
Has anyone tried this? I'm thinking about it!

 

[Steve737]

Not a bad idea, I'm sure it's been thought of before though.

 

[TheBloodyIrish]

That would be awesome, considering buying one of those sunset/sunrise dimming timer cost about $200.

 

[Dr Joe]

Yes it is pretty cool.

I designed a system for a client like that, just used 3 lamps all on top of the tank (fish don't seem to like bright light coming in from the sides). 1) 24" 'morning' in-between 2) 48" daylight bulbs. Sequence.. morning bulb triggered by light sensor on window comes on till mid-morning then addition of 1 daylight bulb. Noon second daylight bulb comes on. Mid-afternoon 1) daylight bulb goes off. late afternoon second daylight bulb goes off. Sundown, sensor shuts off 'morning' bulb. 3 hours later 2) sets of moon lighting come on (varies 1-2 sets during month to simulate phases of the moon). Client was happy with it but never sought to finish the patent process.

Dr Joe

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[portabuddy]

i got that on my 90. 4 48" florecents(2blue, 2 normal) come on at 7:00 then at 10:00 two compact florecents come on then at 12:00 the other two come on, its prety cool, then at 6:00 two turn off then at 8:00 two more then at 10:00 the florecent lights turn off, and the moon lights stay on, and when the full moon hits i point the leds, down at the tank to provide a more direct light...

my other two tanks just turn on and off at 7:00am and 10:00pm

 

[Viverr]

It would be really interesting to have a moving (motorized) bulb mounted onto a variably conductive track acting as a guide, like a double-ended plastic potentiometer.

You could use a convex track to start low to the water level at one end of the tank, and have the bulb move higher as the resistance decreased, then lower as it increased again to control bulb and tank temperature. Maybe a relay on the other end to move the track backwards overnight with a set of LED's for moon lighting. That way you'd get the movement and varying light density for both cycles.

Heck, you could do it with a brush or captive ball roller and a pcb without the solder mask cut to the motor track to control a series of stepped resistive changes.

Just some thoughts. Sorry to jump in after the discussion...
-V

 

[Dr Joe]

It would be really interesting to have a moving (motorized) bulb mounted onto a variably conductive track acting as a guide, like a double-ended plastic potentiometer.

You could use a convex track to start low to the water level at one end of the tank, and have the bulb move higher as the resistance decreased, then lower as it increased again to control bulb and tank temperature. Maybe a relay on the other end to move the track backwards overnight with a set of LED's for moon lighting. That way you'd get the movement and varying light density for both cycles.

Heck, you could do it with a brush or captive ball roller and a pcb without the solder mask cut to the motor track to control a series of stepped resistive changes.
Just some thoughts. Sorry to jump in after the discussion...
-V

As long as we're jumping...

I made one similar for a client (25 yrs ago, old tech now), he even had the tank (450g) facing North / South... The lights came up from end to end for a longer time period. Lights were dimmed at 'sunrise' & 'sunset' and actually replicated light temps / lumen's. Used industrial coil cords (ring contactors were tried and rejected because of humidity and having to have open tracks).

PCB lans will work as a control circuit if it doesn't need very much current, using it straight it will arc up very quickly and become erratic.

Also made one for same client using 20 (!) stationary photo floods (600g tank).

Oh, neither showed any improvement over 'continuous' stationary lighting as in my previous post.

Dr Joe

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