Staggered Photoperiods for Multiple MH?

[AJ_77]

Just read another article on mobile lighting systems - using small electric motors and pulleys to transport MH fixtures across the tops of large tanks... To further simulate natural lighting (the sun tracking across the sky, supposedly).

My Q is this: for people with multiple MH over your tanks, have any of you tried a staggered photoperiod, a left-to-right, dawn-to-dusk effect using timers for each bulb?

For a simple example, say you had 3 MH spaced over your 6-ft tank, with actinics.
- 10 AM: the actinics come on.
- 11 AM: the Left MH bulb fires up.
- 12 PM: the Center MH fires up (2 MH now on together).
- 1 PM: the Right MH fires up (3 MH on together for "high noon" effect).

- 7 PM: the Left MH shuts down, leaving two.
- 8 PM: Center MH shuts down, leaving one.
- 9 PM: Right MH shuts down, leaving actinics only.
- 10 PM: Actinics shut off.

So all MH would be on together for only 6 hrs a day, and each MH bulb would be burning for 8 hrs a day (in this example). And it would look like the light source "rose" at the left, gained strength and intensity through the day, then "set" to the right.

This seems a lot simpler than installing tracks and motors and pulleys, assuming a person wanted to simulate the sun's travel over their reef.

Has this idea been done to death somewhere? Or does it make any sense at all? I don't get on the other boards a whole lot...

[Aquattro]

I don't do this. I can't see any reason to, as it would reduce the total amount of light available for individual corals.

This has also been done to death in other boards

[AJ_77]

Originally Posted by reef_raf

This has also been done to death in other boards

Suppose I could just delete it now...


But seriously, Calfo talks of the angles of the light reaching the corals. etc. You didn't find validity in any of those and other points, or is it just not worth the bother? I'm thinking it might be more fun for someone planning a new tank, or new lighting...

I'm surprised Steve hasn't tried it... or has he?

[Lofus]

But what would happen if you put your frag in backwards and it was expecting light from right to left.....

[Aquattro]

Alan, I guess in my tank the corals get light from all angles. If I turn off one or more of the bulbs before the full photoperiod, the coral loses light from that angle.
What you propose covers the same area, just for less total time than what I use. I had considered this a long time ago, but realized I wanted to do it to make corals happy and make them "feel at home". Well, we all know that the corals don't actually care about home and they don't experience "happy". The light needs to provide energy to elicit a certain physical response within the photosynthetic zooxanthallae living in the coral tissue. The light moving around over the top of my tank isn't going to do a better job of supplying photons to these organisms, and in fact it would lower the overall contact between photons and algae, potentially reducing the amount of carbohydrates produced and thus made available to feed the coral. (=bad)

[Son Of Skyline]

Originally Posted by Lofus

But what would happen if you put your frag in backwards and it was expecting light from right to left.....

Then your tank will explode

[Aquattro]

I'm interested in seeing what others have to say on this subect....any opinions?

[Delphinus]

I think there is maybe some merit to the idea, but I don't know if it's really all that profound. If nothing else you can cover more area with fewer bulbs and maybe there is a cost savings to that somehow. That said, I think a tank that is lit only on one side has a lopsided look to it. I find the same thing with the staggered lights, especially since I keep my photoperiod to somewhat match the outside daylight, and that I'm only around the tank at "high-noon" on weekends, that the likelihood that I will see my tank at one of these lopsided moments is larger.

I might consider something that is a compromise, ie., there is still enough light on both sides to keep the tank balanced but there is something of a hot spot that travels across the reef in a 10 or 12 hour period. If the difference is not unaesthetic (sp?) but enough to "fill in the shadows" then maybe that could be something of a "best of both worlds."

If I was to do such a thing though it would probably be on a track rather than with an array of bulbs. One thing that a track has over multiple-but-staggered bulbs is that you only have to purchase one bulb and one ballast.

I kind of like Brad's point about having enough light at all angles to begin with, but I would think that one disadvantage of a static lighting arrangement is that as corals grow (and grow and grow) the likelihood of their base starting to shade out and bleach/die off, increases over time. A setup that allows me to rearrange corals less often or be pruning less often is something that has some appeal. But ultimately, as with all kinds of gardening, pruning/weeding/culling is not usually something that is postponable indefinitely.

Anyways I don't stagger (other than the dusk/dawn effect) ... I have a hard enough time trying to fit all my timers onto plugs as it is.

[Canadian Man]

Alan,
My light's come on in the order you mentioned but for 4 bulbs instead of three. I don't have it spaced an hour apart though is more like 30 minutes.

I don't notice any benifit's other than I think it looks cool when the 2 radiums are on and then you get the single daylight bulb firing for a very cool effect

[smokinreefer]

i wouldnt believe there is any benefit to the coral to stagger the photoperiod of multiple light sources over a single aquarium.

but there may be a benefit to having the light source move on a track, as it will provide light to the coral from angles that a stationary light source cant provide.