RO/DI system question

[jdnumis]

It is a must have for this filteration system for a 125 reef tank?

 

[nyfynest22]

i would buy one, less of a hassle instead of going back in forth to a store to purchase it.

 

[jdnumis]

thank you

 

[ryangrieder]

i regret not starting my tank with it. my tank been running for a few years and never could get it perfect. now i have to do water change after water change with RO water to fix my mistakes.