I've been using IO for 40+ years, with an 850 gallon system on auto water change, those expepnsive salts are impossible to afford. I order my IO online through Chewy ( No where ever cheaper ) free delivery and you set it up on auto delivery. I ordered salt from them 4 years ago and set up auto ship. I pay $11.00 for a 50 gallon bag ( Yields 46 at 1.026 ) I haven't ever ran out and I always have a few bags in reserve. my Alk in my tank runs right at 8.8 - 8.9. No refugium, carbon dose tropic marin and auto change 45 gallons per week. My reef has transformed in the last year and I owe it all to Neptune Apex Monitoring. Once I monitored the tank for 6 months, then I started adding Apex control. My 850 gallon reef is now steady as a rock. I just ordered new lighting Black Friday. 6 New Radion XR30 G6 lights with all mounting hardware and rails. I have a feeling I'm going to be trimming corals every month starting January !!!! My reef is 21 years old this year, did a complete tear down and bleach bath and hard reset 5 years ago. Until this year with the addition of Apex, this tank is finally almost zero work and headache. Stay slow, stay focused, & stay consistent. Everything else follows in step. Happy Reefing