For the longest time I've wondered why my coffee tends to run either bitter or too watery. I even bought a fancy 64mm flat burr grinder, and noticed the problem became even more pronounced.

Everyone always says how important water is, and I figured my reverse osmosis water with an alkaline stage was probably fine, coming out of the tap at around 50 PPM. It turns out the ideal TDS is actually around 150. My water's TDS was too low. More info here: https://www.raleighcoffeecompany.com/tds-and-coffee/

Using a cheap TDS meter and water alkaline drops, I got my water's TDS up to around 150 PPM by adding a couple drops into my kettle, and brewed a cup of coffee with it. It actually made a difference! Lesson learned, pay attention to your water.