It is always better to manage the nutrients that grow algae by creating competition and reducing the nutrient load than to manage the algae itself. This, however, is easier said than done. Preventative maintenance costs more initially but saves money and time in the long run by preventing more costly issues.

Algae and nuisance aquatic plant growth generally gets out of hand for the same reason the weeds in your garden do. They need sunlight, nutrients, air, and room to grow with little to no competition. Without any one of these factors present, the expected rate of growth can be reduced. Preventative maintenance focuses on controlling these components. Preventative maintenance also involves monitoring the pond for any issues that could reek havoc in the future such as leaks, blocked inlets or outlets and signs of erosion issues.

Nutrients

Surface water runoff - It is important to eliminate all, or as much as possible, surface water runoff from entering your pond. Rain water washes in sediment and nutrients that add to muck accumulation, and weed and algae growth. Grade your pond edges sloping away from your pond with a slight pitch; add ditches, slopes, or tile lines to divert rainwater around or away from your pond.

Floating Treatment Wetland Islands provide a viable option for filtering and improving water quality. Floating Treatment Wetland Islands utilize a buoyant matrix mat and natural vegetation to mimic what occurs naturally in healthy wetlands. The island matrix provides a place for extensive numbers of beneficial bacteria and microorganisms to live, thrive, and compete for nutrients. The islands reduce nitrate, ammonia, and phosphorus while creating additional habitat for fish, frogs, turtles, birds, and other wildlife. Adding aquatic or terrestrial plants improve aesthetics and tie up nutrients and add to the microbial activity.

As water temperatures rise, when nitrates, phosphorous, and nutrient levels increase, algae may start to form and water clarity may become more of an issue. Think of nutrients as runoff, decomposing grass, weeds, algae, leaves, waterfowl waste, dog waste, and bottom organic accumulation on the shoreline and in the water. When these nutrients enter your pond they become fertilizer to fuel algae blooms and weed growth. They can remain in suspension to cause green and cloudy colored water. They can settle to the bottom and contribute to the buildup of muck year after year. This nutrient load and organic muck buildup consumes available dissolved oxygen, especially dissolved oxygen at the bottom sediment layer. These nutrients can be curtailed using a variety of options such as beneficial bacteria, enzymes, activator and native aquatic plants.

Discourage geese - Every goose can contribute 3.4 lbs. of goose manure per day. This adds to your nutrient load and increases the risks of E.-coli bacteria in your swimming areas. You can try to harass the geese and chase them away. You can plant iris, day lilies or other plants that grow thick and 1 to 3 ft. tall on the shoreline. Geese like open easy access areas. ABI has tools which can be used in Wisconsin to deter geese away from your beach area.

Sunlight

Aquatic dyes are perhaps the most commonly used method in lakes and ponds to retard (slow) weed and algae growth and are available in a variety of colors. All plants need sunlight to grow. By reducing the amount of light penetration into the water, the dyes effectively reduce weed growth no matter which color you choose. It should be pointed out that dyes will not stop weed growth, but used consistently, they will greatly reduce it. Lake and pond dyes may also used to improve the appearance of your water.

Pond dye works best in ponds with good water clarity and only retard weeds and algae that are growing at the bottom of the pond, a good rule of thumb is that pond dyes will not affect any weeds and algae that are already in existence, only new growth. Pond dye can be used year round. Normal treatments generally last 1 - 3 months in contained ponds or lakes. How long the dye will last for you will depend on how much flow you have going in and out of the pond.

Air

Dissolved oxygen is the single most important water quality parameter. Adequate aeration lowers e-coli bacteria and helps maintain much healthier water for swimming.  We aerate many municipal swim ponds just for this reason. Dissolved oxygen creates a favorable environment for aquatic life; especially the natural bacteria and microbes that help maintain clean healthy water. Adequate aeration helps lessen algae's preferred growing environment, provides the friendly environment for beneficial bacteria which in turn feeds on and reduces accumulation of bottom organic sediment, and keeps fish healthy throughout the winter and summer. Aeration also allows you and us to use many other effective tools to help improve water clarity and water quality.

Limit Room for Problem Plants to Grow

Limiting room for unwanted species of aquatic plants and algae to grow by introducing native aquatic plants and maintaining your fishery.

Native aquatic plants are another preventative maintenance tool. Aquatic plants both in the water and along the shoreline enhance the beauty of lakes and ponds while helping to0 filter water and compete for nutrients that could otherwise be fueling algae blooms or excessive weed growth. Preferred aquatic plants and their root systems also help stabilize the shoreline and sediment layer. Aquatic plants compete for the space where algae, cattails, grass, weeds or other undesirable plants would otherwise grow. Preferred aquatic plants grow in and at the edge of water out to about 18 in. of water depth and can be introduced in rows, clumps, or intermittently between rocks.

Always purchase from a local vendor in your state. Purchasing plants over the internet or from a different area puts your pond at risk for invasive aquatic plants and/or animals to be introduced. Your state department of natural resources or county land and water department should have a list of aquatic plant growers where you can buy from.

Stocking your pond with fathead minnows and game fish is a tremendous tool in your preventative maintenance plan because fish effectively sequester nutrients in their tissue as they compete in the food chain. One pound of fish sequesters as many nutrients as 350 - 500 pounds of dried weeds or algae (depending on whose research is sited). Occasionally, by removing fish, you are removing nutrient biomass and nutrients which help improve water quality. Routine stocking may be necessary to maintain balanced fish populations and abundant fish for recreational purposes. A healthy, balanced ecosystem is a great way to enhance your fishery and water quality at the same time.