in my interpet fish box there is a plastic removable sheet under the lights can i remove it?
It sounds like you’re talking about something that would normally be between the bulb and the water – so that’s how I’ll answer: If you are talking about a very thin plastic sheet that can be peeled off (like plastic wrap for food) – it’s only there to prevent damage during shipping. But, it the sheet has any thickness (ie 1/16” or more), then no. Without a barrier, water vapor will condense (become liquid water) on many parts of the light fixture as it cools during the night. Over time, that liquid water can corrode the metal contacts the light fixture and/or create an electrical short.
