Hi All. I was sourcing for the above mentioned (w/triple 21 gram basket) and always thought that it can also fit my existing 7 or 14 gram filter basket that comes along with my original portafilter. But the seller was saying "...and please let me know as I've only heard of using the triple (21 gram) basket to control the amount of water from passing through the coffee too quickly"....so can I actually remove the 21g filter basket and fit my 7g filter basket so as not to waste too much coffee grounds just to check on my tamping skill? Thks a lot.

That's what I think so also...most likely to be mis-informed...what I know is that bottomless portafilter filter can fit 7, 12 & 21 filter basket and interchangeable.