Upgrading light question

[roadking05]

I'm upgrading from 72g bowfront with 260w PC light to 90g with current 516w MH with t5.
2x150w MH and 4x54w T5. I have a lot of LPS(no more room in my 72). How do I go about upgrading without hurting my corals? I heard of bleaching from sudden change.

 

[saltwater4life]

If i was you i'd move everything over to the 90g and slowly leave the new lights on longer every week or so maybe by another hour every week. I'm not really sure as i havn't upgraded a reef before but that's what i've read

 

[IrradiatedReef]

With a crouded tank its a little more difficult. But you will want to place everything as low as possible and work the pieces up slowly to the respective places you want them to sit. I have seen people use light diffusers on the top of the tank to help shadow the light a bit.

 

[mfisher2112]

If possible, you might want to start the fixture itself up higher than normal over the tank at first as well. That's a pretty big jump in light reaching the bottom of the tank.

When you make the move to the 90, is it possible to keep the old lights on the new tank at least for a few days or so? That way the corals only have to adapt to being moved first, then adapt to the new lighting, as opposed to all the stress all at once. Just a thought.

 

[roadking05]

My PC lights will fit on my 90G. I also heard of screen method. What kind of screen do I use? Thanks for all the info

 

[mfisher2112]

I've never used the screen method, but I think what they are refering to is plastic light difuser (egg-crate) that you get at lowes or home depot. If you have a dremel, it is super easy to cut to fit the lip of the tank.

Someone else can chime in, but I think the screen method of difusing the light is used in conjunction with lowering the lights slowly to the desired height over the tank. And then eventually removing the "screen".

 

[mladencovic]

I've never used the screen method, but I think what they are refering to is plastic light difuser (egg-crate) that you get at lowes or home depot. If you have a dremel, it is super easy to cut to fit the lip of the tank.

Someone else can chime in, but I think the screen method of difusing the light is used in conjunction with lowering the lights slowly to the desired height over the tank. And then eventually removing the "screen".

You have 3 choices:

1. Acclimate by time exposure: start with exposing them for only a very short period of time (say 15 min) and gradually increase (lets say by 5-10min) daily.

2. Acclimating them by distance: start with corals very far from the light and gradually bring them closer. You can do that by either moving them (placing them at the bottom and then moving them up), which might be impossible in well established and grown tanks, or by moving the fixture very high and then bringing it slowly down, which might be impossible as well due to the limitations of the setup.

3. Acclimating them by filtering: start with placing something in between the lights and the tank that will greatly reduce the amount of the light reaching the water. Eggcrate has a 1/2" openings that will be too large and will not screen anything. Several layers of window/door screen IF PLACED FAR ENOUGH from the MH bulbs so that they do not melt, will do the trick. Each screen blocks approximately 15% of light, so 5-10 will be enough. Or you can go with layers of plexiglas, or some plastic foils, or even glass. Then slowly remobe layer by laer over longer period of time.