My mother-in-law's hose has a soft rubber connecting attachment, along with a [clamp mechanism that is tightened/losened by a flat headed screw... sorry, their real name has escaped me]. This worked pretty well to fill up the 540l originally, we just had to wrap a towel around the tap/rubber attachment to soak up the few high-pressure leaks.
Ever since then I've used my two dedicated fish buckets holding 5 gallons in total, to carry fresh water down to the garage (typically ~4 times to give ~15% water change)... But the more I read on here about member refilling from cold tap on their tropicals, the more I'm tempted to do this with my cooler tamp requirements riverine fish!