Do these tablets descale my espresso machine?

No. They target coffee oils and residue on parts like the portafilter, filter and shower screen. Limescale removal needs a separate descaling product.

How often should I use one?

Breville generally suggests cleaning the group and backflushing on a regular schedule, more often with heavy daily use. Follow your machine's manual for the interval.

Do they work in other brands of espresso machine?

The tablets are described as compatible with Breville machines and other leading brands. Check your machine maker's cleaning instructions before use.

Can I use them in an automatic cleaning cycle?

Tablets are meant for soaking and backflushing small components. Machines with a programmed cleaning cycle usually call for a specific liquid cleaner, so check the manual.

Are they safe for septic systems?

The formula is biodegradable and phosphate-free. That reduces environmental impact, but it is still a cleaning product, so dispose of used solution as your local rules advise.