The Altosid 30-Day Briquets would be appropriate for your needs. The manufacturer recommends that you use 1 briquet for every 75 sq ft every 30 days.
Yes, the Altosid Briquets 30 Day (100 briquets) are applied at one briquet per 100 sq ft in up to 2ft of water. Adding an additional briquet per additional 2ft. We also offer additional larvicides such as Altosid Pro-G and Mosquito Beater for smaller areas.