An RO question

[Katie]

Can someone explain the benefits of an RO system on their tank? An how they work? I am seriously considering getting one and have no idea what I should be looking for.
Thanks

[Merrilyn]

Katie, is the simplest terms, RO units push normal tap water thru a series of filters and finally a very fine membrane. The end result is very pure water devoid of all salts and minerals. On it's own, it cannot support life, and needs to have either a certain amount of raw tap water added back to it, or commercial products to bring it back to water suitable for tank use.

Hobbiests who have very hard water, and are trying to keep or breed soft water species will often invest in an RO unit to keep up with water changes.