Blood in Pool Water

Germs found in blood (for example, Hepatitis B virus or HIV) are spread when infected blood or certain body fluids get into the body and bloodstream (for example, by sharing needles or by sexual contact). Chlorine kills germs found in blood and CDC is not aware of any instances in which a person has become infected with these germs after being exposed to a blood spill in a pool.

Does chlorine kill the germs in blood?

Yes.  These germs do not survive long when diluted into properly chlorinated pool water.

Swimmers want something to be done after a blood spill.  Should the pool be closed for a short period of time?

There is no public health reason to recommend closing the pool after a blood spill. However, some pool staff choose to do so temporarily to satisfy patrons.

 http://www.cdc.gov/healthywater/swimming/pools/vomit-blood-contamination.html