Yes, when fighting an algae bloom, you need to keep your chlorine at shock level for your CYA until the pool clears, the algae is gone, and you are not losing more than 1 ppm of chlorine when testing at night after the sun is off the pool and again in the morning before the sun is on the pool. After you've met all three of those conditions, then you can let your chlorine drift back down into normal ranges for your CYA.

Janet