Do not disable last active node in pool

Not my direct worries. Managers worriy that the monitor will fail and the application will still work. I have setup Irules for maintenance site display if poolmembers go to 0 and redirect to alternate site. I also have sitescope monitors running the exact same checks as the F5 so if something is wrong there will be an alert. How would I go about creating an IRule to send traffic to a different pool? And can the pool contain the same members, just without the health checks enabled? Thanks