Excessive algae blooms are a sign that your lake is already sick
Algae blooms are fueled by excessive nutrients in the water column. These nutrients may be due to new inflows – agricultural runoff, septic or wastewater discharges, decomposing leaves every fall, or the in-lake nutrient stockpiles that have built up over many years in the sediments.
The algae dies off in winter and falls to the bottom and decomposes to form organic nutrient rich muck again.
So nutrient recycling acts to fuel annual algae blooms.
The most popular way to make things worse is to use chemicals – either algaecides or phosphorus precipitants.
Algaecides quickly kill algae so that the dead algae fall to the bottom to decompose and perpetuate the nutrient recycling.
Such as alum that clear the water and precipitate phosphorus down into the sediment to perpetuate nutrient recycling.
The only way to effectively address the problem of nutrient recycling that promotes annual algae blooms is to withstand the temptation to go for symptomatic chemical treatments and rather address the root causes in a systemic manner. This means depriving the algae of nutrients, promoting nutrient uptake by a productive food chain so that the nutrient-rich sediment stockpiles can be worked off and depleted.
In order to do this, you must: