How do you make smoke simulations last longer instead of dissolving after a few frames?

Iv’e got a long domain and a flow object, I’m trying to figure out how to make a very long cloud. Currently the cloud I have dissipates/ dissolves after a certain amount of frames or time, so its only about 15 blender units long I’ve been trying to find the answer on google for hours. I remember it was called lifetime a few versions ago, couldn’t find it anywhere. I looked in the blender 2.8 documentation and its apparently called flame rate, couldn’t find it anywhere. So I went and just started adjusting variables in the flow and domain objects to try and get a long cloud. Still didn’t work! So please, I’m on my last leg here, how do you make a long cloud (think 100 or 200 blender units) in blender 2.81.15?