The bathtub sump

An old cast-iron bathtub serves as the sump, with a recycled door installed on top to keep out the leaves and frogs. From here the water is pumped back to the fish tanks by a RIO HF 17 pond pump, which provides enough flow to keep the bell siphons working reliably. The pump only draws 45 amps, so during the day it easily operates on electricity provided by a 60watt/5 amp solar panel installed on the shed roof.