Seachem

You will inevitably see small shifts in pH throughout any given day; this is due to CO2 gas-off and other things that are occurring chemically in your tank. (This is a normal occurrence for any tank.) With that said, after initially achieving your target pH, it should stay within the range of 7.8-8.4. You can add it if needed between water changes to maintain your target pH and KH, but you should not need to do so more than once every 2-3 weeks. Generally, you will only need to add it with your water changes.