No, check valves are a false sense of security and can and will fail. There is no need for one as long as you have a properly designed return system and keep a little freeboard in your sump to contain the very small, easily calculated amount of water that will siphon back during a power outage. In my 100G that is a maximum of 3.4 gallons going back to my 30G sump before the return is exposed to atmosphere and breaks suction. We all know water can't jump uphill so you have an air gap, the most foolproof maintenance free form of backflow prevention know to man.