How to temporarily reduce rent until lease expires

[Graeham Ford-Feliz]

My property management company left things out of the lease and the tenants filed for mediation and are asking for below market rent.

It hurts, but I'm okay taking the hit on the remaining 6 months of the lease, but want to protect myself from being subject to California rent control if the tenants stay beyond the initial lease.

I don't want to be stuck below market for any time beyond the initial lease.

The tenants are college students with lawyers for parents/co-signers (adding this to my book of red flags!).

How can I, in a way that will uphold in court, reduce rent temporarily for the remainder of the lease and then be free to set rent back to the original rent price at market rates?