Do not fertilize your lawn. If you must fertilize always do the following:
Use a product that contains no phosphorous and has a slow release nitrogen. Your grass doesn't need phosphorous in the fertilizer, but algae thrives on it.
Be aware that through runoff, you are also fertilizing the lake. One pound of phosphorous may produce over 10,000 pounds of weeds and algae. Apply the fertilizer when the grass is actively growing to minimize the loss of nutrients. Cease using fertilizer before the grass stops growing in the fall.
Do not fertilize prior to rainy days.
Leave a 10 foot strip of lawn unfertilized along the lakefront, more if you are on a steep slope.
Install a greenbelt of vegetation between your lawn or septic tank and the lake. Use plants that do not shed their foliage into the water.
Prevent erosion by perforating your lawn, periodically adding seed, and mulching exposed soil.
Keep yard waste out of the lake. When you mow, do not let the cut grass blow out onto the lake. Remove fallen leaves and branches near the shore. Grass and leaves will decompose in the lake and create food for weeds and algae.
Remove aquatic weeds and other debris that wash up along the shore to prevent them from decaying in the lake.
Remove animal waste (dog droppings, goose droppings, and duck droppings) and deposit in the trash or compost.
Remove ashes if you must have a fire on the lakeshore, so that they do not wash into the lake.
Keep chemicals out of the lake. Be careful not to let chemicals from the house or garage spill where they may run into the lake, be washed in the lake, or soak into the groundwater.
Don't use storm sewers. Do not pour oil or other materials down storm sewers. Do not hook washing machines up to storm sewers. Disconnect downspouts from storm sewers.
Look for other ways to prevent erosion. Check around the lake for situations that are either causing erosion or fill in the lake below the high water mark. These add to the nutrient load of the lake.
Do not release aquarium fish, plants, or snails into the lake. The plants can survive and some species have become nuisance weeds in lake wide proportions. The fish can carry disease to which our native fish have no resistance.
Discourage the presence of geese and ducks. Do not feed the geese and ducks. Spray the shoreline with repellent (or Welch's white grape juice).