Hi guys getting ready to fire up my 120 gallon and was planning on using my previous ro/di but wondered if technologybhad advanced since my last reef tank about 4-5 years ago? My wonder is back when I would ‘brew’ new water the ro/di had so much waste water it seemed crazy. Have there been any advancements or new systems that are more Efficient and wastes less water? I have a 3-stage with DI on the end but not against getting a new one if it saves me in the water. Does a 4,5 or more stages make them more efficient? Just looking to keep my water bill in check and not waste if I don’t have to? Any help or tips would be appreciated thank you