Schism
Aquarium Advice Addict
Most people do, its highly recommended. Way too many thing can go wrong from using tap. Most fish stores sell ro/di for $1 or less per gallon. However buying an ro/di unit is more economical as it pays for itself jn less than a year compared to driving and paying 1$ per gallon. With your own unit you produce pure water 0tds for pennies a gallons.