no phosphoric acid involved - the "active ingredient" is an organic compound called a chelating agent ... quite like the medical chelating treatment to remove heavy metals from your system, it binds the rust to itself and allows it to be flushed away

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics