[InMice]

Of course, a reverse osmosis filter system made of...Plastic.

[aardvarkr]

Honestly what else are you going to make it out of? Metal? What about rust? Horrible idea to make it out of metal.

[dghlsakjg]

Is this sarcasm?

Rust is fine to consume, but there are also metals that don’t corrode in water.

[malfist]

Semipermeable osmatic membranes cannot be made out of metal