Pool Chemical Cheat Sheet __link__ -
He understood now. A pool isn't a bucket of water. It's a living chemistry set. It’s a covenant between pH and chlorine, a war against invisible invaders, a constant negotiation with the sun. The cheat sheet wasn't instructions. It was a map of a fragile kingdom—his kingdom—and for the first time, he knew how to be a decent king.
The middle of the sheet was a cautionary tale. Cyanuric Acid (CYA): Sunscreen for chlorine. 30–50 ppm. Above 100 ppm? You've built a prison. Chlorine can't escape, but it can't work either. Only draining the pool sets it free. Mark tested his CYA. 180 ppm. He had been using stabilized chlorine tablets for three years. Each tablet added a little chlorine and a lot of CYA. He was slowly poisoning his pool's immunity. The sheet’s solution was brutal: Partial drain. No shortcuts. pool chemical cheat sheet
At the very bottom, faded nearly to white, were the last two rules: Never mix chemicals. Ever. Trichlor + Cal Hypo = fireball in your face. Add acid to water, never water to acid. Mark looked up from the sheet. His pool was no longer green. It was a milky, confused blue—the color of dawn after a bad night. He set the filter to run overnight. He put the cheat sheet back in his own bucket. He understood now
Next, a drawing of two ghosts. Free Chlorine (FC): Your knight. 1–4 ppm. Combined Chlorine (CC): The monster your knight has already slain. If CC > 0.5 ppm, you smell "chlorine." That's not chlorine. That's chloramine—the stench of victory rotting. Mark had always thought a strong chemical smell meant a clean pool. The sheet taught him it meant a dirty pool. The smell was the pool begging for more shock to burn off the used-up fighters. He learned the 10x rule: to break chloramines, you need 10 times the CC level in free chlorine. His CC was 1.0. He added 10 ppm of calcium hypochlorite. The next morning, the green was gone. The water was cloudy, but the green was gone. It’s a covenant between pH and chlorine, a
And then, a note on calcium: Calcium Hardness (200–400 ppm): Too low, and the water eats your plaster like a sugar cube. Too high, and it rains scale—white flakes of regret on your tile line.