light mover

[davejnz]

I have always wanted to rig up a light mover for my MH.It would help my tank considerably because i only use 1 MH.It would really only need to move 3 times a day.Has anyone ever built one?Got any links or ideas on how to do this?

[dakar]

You mean like moving a pendant type fixture up and down over the tank? Assuming you'd want it to be automated too?

[davejnz]

Yes,say starting at the left side of tank for 3hrs,then moving to middle for 3,then moving to right side.It would be nice to have it automated.

[davejnz]

I really think it would help corals grow in all directoins rather than towards the light.Kinda like the sun moving across the sky.

[davejnz]

basically,rig the reflector/bulb up to a track.Figure out a way to move it on the track with motors that were timed and geared to move the bulb a certain distance.I could always re-set the reflector/bulb at the end of light cycle back to the "dawn"setting by hand .I got the idea,just need some of the technical know-how to get it done.I'm good with electronics/wiring and carpentry/metalworking but engineering it and making it functional w/motors/gearing/timers/ is where i need help.

[dakar]

Kinda thinking out out, but how about just rotating the fixture itself (picture a a central axis above the fixture) would accomplish the same thing? I'd think that would be pretty easy to accomplish with a little thought, a 1-3 rpm motor and some sort of timer. Maybe getting a couple or more passes a day would be even better?

Or something more elaborate, and proably less pretty to look at like the old closelines with pulley's used at each end might work, a little light gearing, again a 1-3 rpm DC motor should be able to do that, might need some more electronics though for positioning, locator switches and stuff.

[davejnz]

The only prob with that is that i use a perpindicular reflector on a narrow(12.5") tank.By rotating it on a central axis i would be distributing alot of the light out of the front and back glass due to the reflection charecteristics of the perpindicular parabolic reflector.For this to be effective in my tank,I need it to move left to right.Thanks for your ideas,If you could assist me(esp. with the motor/gearing/timing)in this project please PM me.If I cant get this accomplished,I'll have to get another halide which i really dont need with a mover in use.

[davejnz]

I've heard of light movers being made and used efectively(mostly on huge growout systems) just never seen one in action.IMO,they are a great idea because they would create a more natural environment.the light would be hitting the corals at all sides instead of just uni-directional.It would save money/energy by not having to add another Mh to avoid "shadowing".Would stop uni-directional growth.

[Reef_Angel]

Interesting idea Davejnz. It would mimic a days normal cycle a little more closely. Did you read something about this or what brought on this brain child? it would insure that all sides of your corals would get light, not just the direct tops receiveing the main amount.

[dakar]

Didn't think it thru ehough, rotating the fixture would really not do anything more than throw shadows, regardless of the orientation to the tank unless you used mirrors to actually bring the light down.

Maybe a better way would be to suspend it on a track and use a stepper motor to drive it back and forth, how much travel distance are you looking at for a complete pass (tank length minus fixture length)? How long of a photo period? Trying to get the majority of the variables together, I have a guy at the office who's pretty smart about steppers and stuff like this, I can pick his brain a bit Monday and see what he can come up with. Biggest factors I can see right off would be how much load could be moved to the bearing surface to be taken off the motor, then a failproof way to may sure the pendant changes directions when needed. I could invent a computer controlled way to do it using the parallel port, but adding that and a stepper motor and controller will start getting expensive quickly, but he's probably got a much simpler method using something that already exists, I tend to complicate things unessarily.