I have a generic tank cover. By that I mean, it is just the regular old tank cover with plastic on half where you sit your light and the other half flips open. I hope that makes sense. My light is fine for what I need since I don't plan on adding any corals or anything. But is this tank cover ok or do I need something better? I haven't had any problems but I just want to make sure it will be ok. Should I be keeping it open or closed? Thanks for your help!