Preventing loop with resilient network connection

Apologies if this is a very basic question... 

We have three network cabinets.

Each has a M4300-48XF (XSM4348FS) managed switch. 
Clients are connected to two different VLANS (VLAN 10 and 20) which are common across the three cabinets.

We're now looking at how to make the network more resilient by linking the switches in cabinets 2 and 3.  The idea is that a break in any of the links won't cause any downtime to the clients.

If we simply add a fibre link, on a tagged port at in cabinets 2 and 3 will this work or do we need to set up anything to prevent loops?

Thanks in advance 
(ps. Next project - adding a second link to the internet, but one step at a time!)