Just got this custom 220 for a steal. The original overflow had one 1/2" hole for the entire drainage; what kind of filtration did the previous owner run? Anyways I drilled two new 1" holes and put in two 1" bulk heads for my refugium/wet dry sump. There's this random pvc pipe 1/2" big that comes out of the over flow. That chamber that the pvc is in, does not connect to any other chamber nor is there a hole at the bottom of the tank. What is its use? Here are some pics
