I did a few things. 1. Connected an air tube to my skimmer, and pulled it to somewhere else with fresher air. Didn’t help much. 2. Added more aeration and agitation to water surface. Didn’t help much. 3. Increase white light, so there more photosynthesis during day time, and use up more carbon dioxide, didn’t help much. 4. Added a container to put in chaeto (basically an algae reactor), operating opposite time to my tank lights so something can consume CO2 at night... helped a little, but PH still registered low. 5. Use a different test kit to check my ph.... problem solved. Lol.
this went on for about 2 months before I knew what was wrong. Seneye.