--- title: "What Is Cryptosporidium? Pool Glossary | Marina Pool Services" description: "Cryptosporidium is a chlorine-tolerant germ that can cause illness in pools. CDC has guidance on it." url: https://marinapool.multisites.ai/glossary/cryptosporidium publisher: Marina Pool Services phone: +1-817-896-1120 quote: https://marinapool.multisites.ai/contact --- Spa and safety # Cryptosporidium Cryptosporidium is a chlorine-tolerant germ that can cause illness in pools. CDC has guidance on it. CDC lists Cryptosporidium as very chlorine tolerant. A swimmer with diarrhea can spread it even in a well-kept pool. Normal chlorine takes a long time to kill it. Simple rules protect everyone: do not swim sick, rinse before you swim, and take kids on bathroom breaks. If a fecal accident happens, follow CDC's cleanup steps. See [recreational water illness](https://marinapool.multisites.ai/glossary/recreational-water-illness). Keep sanitizer in range every day. Keep sanitizer and pH in range every day, and do not let sick swimmers in the water. ## Related terms - [Recreational water illness](https://marinapool.multisites.ai/glossary/recreational-water-illness) - [Free chlorine](https://marinapool.multisites.ai/glossary/free-chlorine) - [Chloramine](https://marinapool.multisites.ai/glossary/chloramine) ## Sources 1. [CDC: Home Pool and Hot Tub Water Treatment and Testing](https://www.cdc.gov/healthy-swimming/about/home-pool-and-hot-tub-water-treatment-and-testing.html) 2. [CDC: What to Do When There is Poop in the Pool](https://www.cdc.gov/healthy-swimming/response/what-to-do-when-there-is-poop-in-the-pool.html) ## Need a hand with your pool? Call or text and tell us what your pool needs. Estimates are free for qualifying services, and same-day estimates are possible when the schedule allows. [Call (817) 896-1120](tel:+1-817-896-1120)[Get a quote](https://marinapool.multisites.ai/contact) ![A pool technician working on an equipment pad](https://marinapool.multisites.ai/_astro/technician-equipment-pad.BW5xZMNY_Zum1K5.webp)