I go with the idea of using it as is. But then I can't see how bad the silicone might be! My thinking is that if there is going to be a leak at some point in the future, it will not be a great big sudden failure but a slight ooze. That leaves me thinking that if the algae buildup under parts of the silicone is not enough to bother you, I leave it but also have a backup plan kind of formed. Just in case? Maybe think of what to do with fish, etc. if you found an ooze that required draining the tank that day to avoid water damage. At first a towel will be able to catch the water for a day or so but not keep it off the stand or other things as it begins to get worse. Just part of being prepped for bad things that might never happen.