Things to watch for when changing lighting?

[Aquattro]

Also, reducing the photoperiod may not be enough. If the intensity levels cause too much photosynthesis in the short period, too much O2 can be produced within the tissues and damage can occur. Enzymes normally control this, but if O2 production is greater than enzyme response, you lose tissue and or zooxanthallae. Rigging the timer to go on and off every hour with an increase in the on period is a better way. the layered screen thing is good also.