The PRO T maxes out at just over 2.5gal per day and runs at >70mL/min and the flow rate can not be adjusted outside of manual mode Any auto setting will run the doser at its preset flow setting. The PRO is really is more of a small titration pump ideal for ATO, two-part, and small water changes. The Kamoer X2SR is a dedicated water change system capable of better managing your daily water change with larger robust pumps and tubing. This will get a water change done in less than an hour and the app is dedicated to the process: https://www.coralvue.com/kamoer-x2sr-water-change-system To accomplish water changes with the PRO T you would have to start it much earlier and likely run 10-12hours to equate to ~1gal pumped. Hope this helps.