The Definitive Dark Knight Guide

[Gonzu]

Salted earth is always a DPS gain, even on a single enemy. It is off GCD and a has no cost

I know this. I meant another - Salted Earth has a cast time (1,5-2 second to aim and use it). Rationally use it on one enemy, or better to spend those 2 seconds on other abilities (such as starting a new combo)?

And later

Salted Earth: Deals 75 AoE damage for 21s = 525 potency

I think 1 tick occurs every 2.5 seconds, 21/2,5=8,4 ticks, 8*75=600, or no?