I own a swimming pool and do most of my own maintenance and water chemistry. I created https://poolforthought.com https://poolforthought.com as a place to orga

I own a swimming pool and do most of my own maintenance and water chemistry. I created https://poolforthought.com https://poolforthought.com as a place to organize my knowledge. I later realized other people want the same info, and now 7 years later it's made about $20k USD. Ads and affiliate links drive site revenue. I have about 12k email signups of people who want a pool maintenance ebook I'm creating (for a price). I should finish that thing. It's money just sitting there waiting for me to capture.