Nems and Too Much Light??

[patchin]

I've had a GBTA for a couple of years and he's been happy and sedentary. Right about the time I switched to a 175 Iwasaki 15 K it took off and now very high on the back wall. I recently got a RBTA and put down where the other one started out and it immediately took off and also ended up high up in a corner. It's a 50 ga tank with the one halide and a little actinic supplementation. The fixture is 2 inches above the water. The RBTA came from a tank with t5s. Do you think it's too much light?

 

[Euphyllia]

It could be a lot of things: flow, feeding, etc.
Did you acclimate them to the new light?

 

[sid700]

Do you think it's too much light?

Mine is finicky that way. Even just shifting the position of the reflectors a bit, the 'nem would move.

I'm guessing it's now acclimating to the new bulbs by moving away from the direct light.

 

[patchin]

It could be a lot of things: flow, feeding, etc.
Did you acclimate them to the new light?

I raised the fixture a couple inches for a couple of weeks. I think it has to be the light.

 

[hiepatitis]

I'm gonna say lighting too. Unless something else changed there seems to be a link since the nems moved right after the light change.

 

[Euphyllia]

It could be a lot of things: flow, feeding, etc.
Did you acclimate them to the new light?

I raised the fixture a couple inches for a couple of weeks. I think it has to be the light.

Raising the fixture won't have much affect in acclimating the corals/nems to a new light. Try putting four layers of window screen over the tank and remove one one every three or four days.

 

[houser]

Raising the fixture won't have much affect in acclimating the corals/nems to a new light.

Incorrect. Raising the fixture can often reduce the illumination levels at a particular spot, or in some cases actually increase the illumination level at that same spot. It is all about the geometry of your reflector system. The changes can be dramatic.

Try putting four layers of window screen over the tank and remove one one every three or four days.

Can't argue with that, although you probably should have suggested Steve use finer mesh, since some types attenuate by 40% per layer.

 

[Sfork]

I have an old float mag cleaner that i siliconed a cut sheet of black plastic canvas to. I add it to the tank to block some of the light to acclimate new corals.

 

[patchin]

I doubled up some plastic screening and placed it under the fixture.

 

[patchin]

The two layers cuts out a lot of light. Should I try to move the nems down or just hope they move on their own?

 

[sid700]

I've directed powerheads to nems so it will stay away from corals. It works to a point, it would go the other way, but I can't really direct them to a spot. Its just moves to where it wants, really.