I plan to buy Safe once my prime is gonePrime does have a rough smell. Price wise I find it to not be quite right for myself. I use Safe, which is the powder form of Prime. Measure out the quantity I need for water changes into a five gallon bucket along with my other additives. Safe still smells like a bucket of buttholes, but in the powder form usually only smell it when closer to the can. Once mixed it's barely discernable. And at a 1/4 teaspoon for 300 gallons, it's the best price wise since I'm caring for eleven tanks.