so if i have 4 fans for my pc i can use 3 of them in the chassis right and the other one on the power supply since my power supply has 4 pin
Are you referring to the molex connector on your power supply? I don't know about that, but you shouldn't need to. You can still connect 4 case fans to your motherboard (in addition to your CPU cooler, assuming it's single fan). Just connect one of your chassis fans to the CPU/Water Pump Fan Connector, and connect the other three to the Chassis/Water Pump Fan Connectors.