Auto Click Alch Speed

Hi guys, does anyone know the exact speed to alch?

I swear I have tried between 1.4 and 1.6 seconds sometimes I alch them all sometimes I don't.

It's very bothering.

 

It varies. Connection (latency), server population (impacts ingame ticks), and other factors apply... just set it at the highest amount (1.6 as you say) and leave it at that for the best option. HA thankfully queues the next cast if you cast it slightly too fast. TOO many fast casts will stack up and create problems (like getting stuck on the inventory screen). That is why I say go with the longer wait period...