I posted a thread a few weeks ago about my plants not doing too well and most people suggested that I had either too little CO2 or a calcium deficiency. Since then, I decided to test my kh and gh and found that they are very low. My kh and gh are both under 2 degrees and my ph shifts from 6.0 (the lowest number on APIs test kit) and 6.4. I was thinking about raising all of these by using Baking Soda and seachem gh booster or adding crushed coral to my filter. I think I definitely need to add kh as a ph buffer because my ph swings kind of often. What would you guys recommend doing?