If I cut my current 50mg/ml down to.. say 25mg or less down the road, I could definitely get by with just 2 gallons. On the other hand, I'd rather be safe than sorry.Looks like I'll be making a big purchase at heartland vapes (or other vendor) this fall. I plan on buying 3 gallons of 100mg nic salts.. which should last me at most 63 yearsat the least 42 years. Not too bad really for $708