If working with saltwater then an ro/di is recommended.
I'm planning on doing another BRS group buy sometime in February. keep an eye out for it.
__________________ 180g- Mostly BIG fish and some coral. ~80g Nuvo- My coral tank with "happy fish"~ 90g- FOWLR Not the not happy type of fish~ 125g- Freshwater Malawi Cichlids ~10g- Nuvo- The refugees from the Ich of '18