Auto Top Off Pumps
Auto Top Off pumps will normally be connected to either a controller or a timer to replenish the amount of water that is evaporated throughout the day. Salt does not evaporate so all top off water will need to be fresh water and not saltwater. Selecting the correct pump for your system can sometimes be a challenge however we have selected a few pumps that we recommend and will fit most reef tank systems of average sizes and evaporation rates.
We normally suggest going with a slightly larger pump than you will need, and putting a ball valve in between the pump and the output of the tubing to control the flow of water coming out of the pump. The other factor to keep in consideration is the height the pump will need to push (head height) to replenish the evaporated water. The higher the pump needs to push the slower the flow because of gravity's effect. Almost all pumps will have a "Max Head Height" which is the point where the pump will not be able to push water any higher.