Is an R.O. unit necessary?
No. I would say its not more necessary than a skimmer. Will it help improve your water quality? YES. If your using prime then i assume your on a city/town water source. Since your at the mercy of the water supply you never really know for sure whats being put into it.
Some are blessed with very good water from their town where as others are not. Going to RO
water can help lower your algae problems, it can help maintain water quality aswell.
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