Rent increase contract per condition

[Jay Yoo]

Hi.

We signed the first contract with tenants for $1650 and 3 students for a 2 bed /2baths property, and $1650 for security deposit.

One of tenants asked me if they have one more tenant shortly after 2weeks.

After some thoughts, I gave a suggestion to them if they agree the below conditions;

-Increase $200 per month

-Additional $400 security deposit

-IF one of them have to move out before the maturity of the lease, the rent goes back to $1650

-IF the remaining tenants cannot pay the rent, the term will end the next end of following month, and everyone need to be vacant and meet the same conditions as before they move in, or security deposit shall be used for repairs and cleaning.

So the tenants agree to my offer since the original three would save and reasonable cost per month.

Of course, I run background check on everyone. And cosign with their parents.

So Should I recreate the rental agreement or should I just add addendums with these conditions?

Would you mind giving me any other advice from legal perspective or your experience?

Thank you so much