How long can I wait before suing my tenant for rent owed.

[Dyani L Washburn]

Hello! 

My tenant moved out without paying the last month and a half of rent.  I know I have 30 days to sent a certified letter stating everything he owes/what I am removing from his security deposit, however I keep seeing conflicting responses on how long I can wait to actually sue for the additional monies he owes.  Due to other issues, I would like to hold off at least until after August- some people say as long as you've sent the letter, you can wait a few years if needed, where others say just 30 days.  

I would greatly appreciate any advice given!

Dyani