So I just started using a puck screen. Is there anything I should know about cleaning it? Is a simple water rinse after each shot enough? Any issues with using Calfeza once a month when I backflush my machine?

Not in my experience. In between shots I brush it off. I rinse with hot water when I'm done for the day. Cafiza soak once a month. Appears to be quite clean before each use.

I've been using them for about a year now. Like you, I usually gave them a good cleaning whenever I used Cafiza. However, with the puck screen, I find I rarely need to use chemical cleaning anymore, or even to lube the group. When I drop the shower screen, the little that's there wipes right off with a damp rag. So, I now drop the screens into a small container with some Cafiza solution about monthly; daily, I rinse and wipe them with plain warm water. Sometimes, I put them one at a time into an empty portafilter (no basket), and give them a blast from the steam wand or the hot water wand. Sometimes, I clean a portafilter in an ultrasonic cleaner, to get everything out of the inaccessible passages; when I do this, I drop the puck screens in as well, along with our jewellery In another thread, someone wrote that he just sticks them in his dishwasher. In any case, I find it odd that they don't seem to get very dirty; not much comes out when I clean them.

i rinse mine with water after i use it. and once a week i soak with cafiza.

Thank you everyone. It's most appreciated.