Can I use household bleach to shock my pool in an emergency?

Yes, if it’s plain, unscented bleach with only sodium hypochlorite (ideally 6% or higher). But it’s weaker than pool shock, degrades faster in sunlight, and risks impurities if you grab the wrong bottle. Use it only for one emergency shock while the pool store is closed—add it at night, run the pump, and test the water the next morning. For regular maintenance, buy real pool shock; it’s cheaper per ounce and less guesswork.