Def an nice RODI set up. Driving an hour each way and lugging a trunk full of 5 gallons jugs to a reef shop (their water has lowest tds) has gotten really old but it’s that or a sky high water bill.
depends solely on incoming TDS whats right for me is probably not right for you. Me? 37 tds so I have 3 ro chambers in series as a water saver after 1 prefilter chamber and 2 carbons. then I have 3 DI chambers inline. All tied in to run an hour a day automatically to keep my 10g kalk reactors water tank full with a inline gate valve to a 100g stock tank used for water changes. Set up for 100g water changes that take 10 minutes tops, and a ATO kalk set up that requires no maintenance at all less cleaning the rust out of off the pre filter and the carbon block changesDef an nice RODI set up.
extra failsafe for the tank and an audible alarm if your temperature goes out of whack, ones on aquarium controllers obv better as you can also be sent updates on your phone as well if it goes offlineWhat makes it safer? Seems like putting multiple small heaters in might be the safest option.