Bleach it for sure. 10:1 water to bleach ratio is highly effective but using more than that is not necessary or even any more effective. Like others have said flush the water changer out and rinse it off in the shower with fresh water then leave the whole thing to soak in a bucket of fresh water with dechlorinator. Don't forget to disinfect any nets or other equipment that move from tank to tank. Wash your hands and arms thoroughly with warm soapy water and make sure they aren't still wet or soapy when going back into the tank.
