Although I don't use cans anymore,....... when I did.......
I found those plastic hose fasteners were basically useless, so I would buy and use metal hose clamps from the hardware store to tighten hoses.
But you must be careful not to over tighten them, because the plastic protrusions the hoses attach to, can also easily crack under pressure, then you're really out of luck.
I stopped using cans, because the cost, compared to the plastic materials used to build them, and because I found them "non user friendly" to do maintaneence on, and the actual filtration they provided was at best, minimal, in that, if enough regular maintenance wasn't done on them, they would spew nitrate, but if a reasonable amount of maintenance was being done, the wear and tear on the cheap materials they were made with, by taking them in and out of service would cause them to fall apart.