2 tanks with one sump

[RedipsNam]

I have a 1 year and half a year running tank and planning to add 2 tanks so total of 3 with one sump so everything is working fine but just wondering if my 2 tanks will be fine with new rocks? or should I cycle it too?

 

[tsharpe291]

I actually did the same thing and I cycled mine before I added it just to be safe.