It is possible but not sure. I have had some problems in one tank that never affected another. Also, even with 2 separate systems there is an high possibility to transfer diseases, unless you use different set of maintenance tools, you never move corals or fish, you wash your hands before to take care of the second tank and so on.
I've found out that with multiple tanks I can invest all my efforts for making it more stable and safe.
If you quarantine and take care of your fish and corals you are not gonna have this problem.