I use citric acid too, but you should know, if your tap water alkalinity is high, citric acid won't maintain the ph for long-its a very weak acid. However if your alkalinity is low, or you're adjusting RO water, citric acid is great. Citric Acid is also nice because it will actually lower your PPMs due to it's reaction with the bicarbonates in your water, unlike Phosphoric acid which will raise your ppms. I use a combination of citric acid and phosphoric acid now, just to keep my ppm increase down. I mostly adjust with citric to start, maybe 2/3 the way to my target, then the last 1/3 with phosphoric. The combo keeps my PH stable for longer than citric alone. Good luck!!