Here’s a tip:-
Tapwater TDS around these parts is appx 375. It burns up DI resin so RO is needed. To use even less DI resin, always run RO only for a couple of minutes before connecting to your DI container. After RO it drops from 250 to 15 over the first few minutes. Check the TDS at first flush and recheck the TDS after a few minutes. When it levels out at your normal low point, reconnect the DI.
If you have a packaged system, fit a push-fit connector on the DI feed.