By reducing the use of fertilizers or by reducing the runoff from farmland after rainfall.
Explanation:
Farmers use excessive fertilizers on farms. This fertilizer is carried by runoff water to the nearby water body. Due to the addition of fertilizers, the water in the water bodies get nutrient enriched thereby causing excessive growth of algae in it (Known as algal boom). If farmers reduce the usage of fertilizers, or somehow take measures to reduce/stop the run off of water from farmland, then this problem of algal boom can be reduce.
When a household installs a dual flush toilet, the water is mainly conserved by limiting its consumption and thus eliminates the unnecessary loss of water. #2 is the answer
Explanation:
A dual flush toilet is similar to a standard toilet but includes some water conserving features.
