An overflow box is an excellent alternative to drilling a hole in your aquarium, especially if you already have a tank and want to avoid the risks associated with drilling.

The overflow box hangs on the side or back of your aquarium and uses the water level to direct water through the box and into your sump system. The box is connected to the sump via pipes that lead from the overflow box outlet to the sump.

The weir in the overflow box helps to prevent fish from entering the overflow and also creates a comb effect, ensuring a quiet, smooth water flow without disruptions. This setup provides an efficient way to filter and circulate water without the need to drill into the tank.