Wrong lesson learned!!!!!!!!!! Or incomplete lesson. HOW MANY TIMES DO I HAVE TO TELL YOU??? Do I sound like your mother? Where is your security feature on your pond? Look at the potential for fish loss. Those who have to buy your water, look at the cost of the water lost. Look at the potential for pump burnup when your pond level gets too low. Think it can't happen to you? In 6 years of ponding, I've had at least 3 near disasters. But I've always had a pump with a built in shut off float and there have been no disasters. Yes the pumps with a float cost more than those without floats but it has paid for itself over and over. Right now I have a leach/leak in the sides of the waterfall and sure enough, DH was adding water to the pond when I got up. Said the pump was off when he got up. So anyway, there are floats that can be connected to your pump that will protect it from a low water problem. And there are floats that add water when it gets down below a certain point.
There was a windy day and a plastic shopping bag blew in the pond. The pull of the intake pulled the bag over the intake of the skimmer and blocked the water enough that the pump shut down. Another time I had put some filter media in a basket where the water enters the waterfall in the Skippy. The media got clogged and was blocking the exit so the Skippy filled up and was running over. DH discovered it when he got up in the morning. There's just two examples and every spring and summer I read several stories of near disasters or disasters that occur when there's no security on ponds.
Anyway, Julles and Ruthie, now that my rant is over, glad your problems had such a simple fix.