I'm not sure if you meant it this way, but you might be right in the sense....

That the dead fry was actually tangled up in the grass, having been moved from the big tank while dead.  And.. perhaps the actual sixth live fry was in the gravel when I emptied the tank.

I -did- find one baby in the very corner when I dumped the gravel and water back in on top of the filter plate, but I thought he'd just gotten sucked down there by the filter.

...that's horrible.  I'm so glad I saw him, or he would have died, buried alive. o.O  I want these guys to live, because they're the only offspring of one of two very special males given to me by a friend of mine... I felt bad about them dying under my care, so I wanted to surprise him some time down the road...