Washers Detergent Usage in the Top Load Washer. Large loads require more detergent than small loads. If your clothes are heavily soiled, increase the amount of detergent. If you have hard water, you will need more detergent. If your water is soft, you may need as little as 1/4 cup or the soapsuds may run over. Properly Using Granular or Powder Detergent: After loading clothes, put the detergent in the wash basket next to the agitator.