Auto top-offs can be an aquarium keepers best friend or worst nightmare. During normal operation, the top-off will automatically fill the sump with a fresh supply of reverse osmosis water. They can even be used to add kalkwasser to the tank. But the top-off can also fail in the on position, causing the tank to fill with freshwater. This can reduce the salinity drastically or even flood your floor.
Tip of the Day – 6/23/20100