Best RODI system for my situation

[jeep and goose]

I plan to have a 75 with a 40 gal sump, what ro unit should I buy, preferably something that is low ish maintenance and high output so I’m not spending 3 days worrying about filling my tank

 

[lapin]

https://www.bulkreefsupply.com/4-stage-value-100-gpd-ro-di-system-bulk-reef-supply.html

 

[HaKs310]

I would suggest you purchase a TDS meter, around $10 on Amazon, to measure your tap water first. Also look up what your city's water source is and what additives they use so you understand what media in the RO/DI would suit you best.
Once you figure that out, you'll be able to purchase a unit that fits the bill. I would recommend either a BRS or Air, Water & Ice unit.

 

[Gumbies R Us]

I plan to have a 75 with a 40 gal sump, what ro unit should I buy, preferably something that is low ish maintenance and high output so I’m not spending 3 days worrying about filling my tank

I use a 4 stage RODI from AquaFx. Never had any issues with it.