After a busy weekend of intensive swimming, or thunder storms, or sultry weather, your pool water will need some extra attention. The water needs time to recover. You can hasten this recovery by carrying out a shock treatment. You simply add an extra dose of chlorine to your water (4x the normal amount, but no more than 300 grams per treatment). This shock treatment really does the job.
If you use Superzuurstof, you can give an extra Superzuurstof boost during intensive use of your swimming pool.