Aquarium in baby's room?

[lindsayf]

I'm having a baby in May and the room we'll be using for him already has a 20 gallon tank in it. I was going to leave it in there since I thought it would be calming to the baby. However someone recently mentioned to me that it is very unhealthy to have an aquarium in a baby's room. Do any of you know anything about this or know where I could look for some details on it? Thanks a bunch.
Lindsay