[petpoor]

Just put in my new ten k ushio bulbs i couldnt stand the yellow of my iwasakis any longer. Question is the iwasaki's are only a month old should i drastically lower my photoperiod with the new ten k's since they are a different spectrum ??because to my eye they look alot less intense than the saki's so was wondering is necessary to go back to about two or less hrs on the ten k's and work my way back up???? By the way these are 400 watters if that makes any difference.

Thanks,
Tom

[tendar]

You dont need to do anything. THe iswakis where stronger than what you have now so you actaully have lower light per par.

[radioactive]

IMO , run the lights like normal , bet it looks nice .....

[Ninong]

The only adjustment you should even consider would be to increase your photoperiod by a couple of hours and then gradually reduce it to where you want to keep it. This is almost as important as the reverse adjustment that would have been necessary if you were going from lower to higher PAR.

Any sudden change in environmental conditions can cause problems for many of the animals in the typical reeftank. Sudden changes in lighting, whether an increase or a decrease in intensity, will cause the animal to have to make sudden physiological adaptations that are stressful. In your particular case, zooxanthellate animals will have to suddenly expel excess zooxanthellae to adapt to the new lower light environment. Daniel Knop has observed that Tridacnid clams sometimes experience local bleaching after a reduction of light intensity.

I am not predicting that you will have problems, I am just trying to explain the situation so that you understand it better.