Rent Increase? Limit?

[D Higgs]

Good morning BP!

Is there a limit on how much I can increase rent of an existing tenant, assuming the lease is expiring soon? I know you have to honor any existing leases if you purchase a new property. Let's say I determine the existing lease is super low and I want to raise $200/ month; aggressive i know, but is it legal? It shouldn't need to be raised slowly over time, correct?

Also, what if I want to make improvements to the units while the tenant is still living there. Can I THEN increase rent amount?

I'm assuming there's some sort of laws in NJ managing that, but I wouldn't know where to start looking. Thanks!

-DH