Hi im taking care of my bf's 150Gallon tank while he's away so i'm kinda new at this. I just did a water change for the tank and everything seems to be fine. However, there doesnt seem to be any water being pumped into the protein skimmer. There is still water in there and there is some foaming going on but i think it may have been from b4 i did the water change. Theres some water flowing out but I have no idea how the water is getting in. I know this might be a stupid question but can someone please help!!!!