You don't need to vacuum but it is advised that you brush the whole pool at least once a day. Best time for this is right after you add the bleach. This helps to mix the bleach through the pool and exposes all the algae to the chlorine for more effective killing.
If you're on a tight budget you may want to try adding your bleach at last light. This way it has all night to work on the algae without loss to sunlight. This may give you your best bang for buck.
If you're on a tight budget you may want to try adding your bleach at last light. This way it has all night to work on the algae without loss to sunlight. This may give you your best bang for buck.