Best Way to invest Security Deposit

[Poppy Pia]

Hello All,

I am a newbie investor and would appreciate
your answers to a question I have ...

I have 3 rental properties and have a total security deposit of approx. $6K from these 3 properties.

Let us assume - not all my tenants will leave at the same time and I can manage to refund each one their deposit (if need be from another source).

My question -
What's the best way to store this money or for a lack of better word - how to make this money work for me?
I know I should have a trust account and keep it but just curious how can I make money out of this money? Or am I getting it all wrong and the best way to keep this is in checking trust account (which almost gives next to nothing interest).

Please pour in your thoughts and bell this newbie!

Thanks for your pointers!