New Lighting - now how do I install it?

[Uslanja]

Good Morning! We made the plunge and purchased a 250 watt metal halide pendant for our tank. We have been running a 96 watt 50/50 power compact for the past 8 months. Things started OK but slowly began to fail. Lack of adequate lighting is our suspected culprit.

Once the light arrives we will need to acclimate our guests to the new intensity, and it will be much more intense then they have been living in! So here is our question; How do we bring the new light on line and get it up too speed? (Shorten the time period the light is on? Hang it higher than normal and slowly lower it? A combination of both procedures?)

We are concerned about harming our tank and occupants. Any advice would be greatly appreciated!

Thanks Everyone

 

[GlassMunky]

Shorten your photo period alot. and then slowly over like a week or two bring it back up to normall. just keep an eye on the corals, some of them may pout at first with the new light

 

[Uslanja]

Hi GlassMunky! So, would we put the light at it's intended/ultimate hight and just adjust the lighting period? This is going to be a major increase in light. We currently run our daylights for 6 hours. What would you recommend we start the lighting period at? Would 2 hours be too much? Also, we we're thinking we would extend the lighting period by 1 hour per day per week until we're up to 6 hours. Are 1 hour increments too much?

Once the lighting is changed and then the lighting period is increasing; what would we watch for to determine if the corals are doing well or not? Bleaching is something we do not want to experience and once we notice bleaching then the damage is already done. Are there other signs that we should be watching for that would indicate the lighting change is to drastic or proceeding just right?

 

[DaveK]

In my opinion, shorting the photo period is the incorrect way to go. You must consider how much light your giving and all at once. It's kind of like going out in the sun after a long winter. You can get a bad sunburn in only 1/2 an hour. And that's you. Your fish and corals can't put on any SPF 25 sunscreen.

The way to do this is to raise the MH lighting very high, maybe 2 or 3 feet above the tank, and/or block part of the light with something like white transparent plastic sheets.

This lets you greatly reduce the amount of light and maintain the original photo period.

Then over several weeks you can increase the lighting.

 

[BobBursek]

Window screen works good to cut the brightness down also, 2 or 3 layers and remove one at a time about a week apart.

 

[DaveK]

Window screen works good to cut the brightness down also, 2 or 3 layers and remove one at a time about a week apart.

A good point and it's very inexpensive.

 

[Uslanja]

We thought about the light intensity being too high even for short periods. Raising the light high and using a few layers of window screening is very doable. So here we go again with another silly question; how do we know after all that whether the light is still too bright or not?

 

[DaveK]

You want to start with it being about the same as what you have now. It need not be exact. You can just eyeball it.

 

[jcgardner]

Window screen works good to cut the brightness down also, 2 or 3 layers and remove one at a time about a week apart.

+1

 

[Uslanja]

OK! This sure does make us nervous. We don't want to hurt any of our guests.

So, we will hang the light high at about 36 inches and cover the tank top with 4 layers of window screening. Then the second week we will lower the light by 6 inches, the third week remove 1 layer of screen, the fourth week lower by 6 inches, the fifth week remove 1 layer of screen, etc......... By the eight week we should be at 12 inches off the tank and 1 screen left. At week nine we are at 12 inches and no screening.

We're not sure where the final hight of the light should be.

Are we going too slow, should we/can we get to the full intensity quicker?

Should we just place the light at it's anticipated final height and go with several layers of screening only?

 

[reef dummy]

That sounds like a good time line. Your corals should be fine with that schedule. You're going to see some amazing growth from your new light.

 

[Uslanja]

Hi reef dummy! We're thinking that 9 weeks to get everything up to speed is a long time, but our corals (mushrooms, ricordea and a montiporis) have been in low light for quite a while. So, we will follow the 9 week schedule and see how things go. Any ideas what we should look for to determine if the lighting acclimation is going correctly?