You shouldn't dose a buffer without testing your alkalinity, you can't fix PH with a buffer. If you keep dosing buffer without testing you run the risk of making the problem worse. How low is your PH? If your PH is between 7.8 and 8.5 and is stable I wouldn't worry about it too much. If you want to try and adjust your PH check your calcium and alkalinity and adjust them if necessary. Once they are in the recommended range if your PH is still low you may have excess CO2 in your water you can test this by putting a sample of tank water in a mason jar or other container with a lid, take it outside and shake it for 30 seconds then open the lid and fan fresh air into the container replace the lid and shake again. Repeat this 4-5 times then check the PH of the sample, if your PH rises you have excess CO2 in your water and need to increase the gas exchange by providing more flow in your tank particularly at the surface.
