Controlling Aquatic Weeds for Good
Keep nutrients in check to control aquatic weed growth
While aquatic plants can enhance your pond in important ways, some are nuisance weeds. They quickly take over and can choke desirable plant life, slow the water movement and make your pond look overgrown and swampy.
Some people will turn to herbicides when faced with this kind of unsightly mess. But beware: although weed killers do quickly kill off vegetation, an herbicidal approach alone can kickstart a vicious cycle of regrowth and chemical dependency.
Instead, we suggest a preventative approach to control those aquatic weeds for good.
The Real Problem Is Your Nutrient Load
Just like algae, aquatic weeds will flourish in a pond that has a high nutrient load. Nutrients are a byproduct of decaying organic matter in the water body, such as fish waste, plant material and fertilizer runoff. The nutrients are retained in the bottom muck and the water column.
Left unchecked, nutrients will serve as an excellent food source for both weeds and algae. It’s your pond’s nutrient load that is the real problem – the weeds you see are the symptom.
If you use an herbicide or manual removal to eliminate existing weeds, ensure that the plant material isn’t left in the water to rot, otherwise it will simply create more nutrients to fuel the growth of a new batch of weeds.
Keeping Nutrients in Check
After treating existing weeds and removing the plant material completely from the pond, you can start a preventative approach to the underlying problem of excess nutrients.
To lower your nutrient load effectively and permanently, fortify your pond with healthy beneficial bacteria. Beneficial bacteria feeds off of the same nutrients that weeds and algae do. A plentiful nutrient-hungry microbial population will compete with weeds for this food source. Eventually the bacteria consumes so much of the nutrient load that the weeds are starved out and struggle to grow.
Three Tools to Support Beneficial Bacteria
Aeration is a significant aspect of the preventative approach. Not only does aeration keep water cool (weeds grow faster in warmer water), it increases your pond’s oxygen level. Oxygen supports aerobic (oxygen-using) microbes in quickly consuming and converting nutrients so weeds stay in check. By helping the bacteria feed efficiently, oxygen prevents large bacterial die-offs which could otherwise cause a nutrient spike and trigger a re-emergence of weeds.
Inoculation is another powerful tool. Inoculation introduces additional beneficial bacteria to your water body to attack the nutrient load. You may need a one-time kickstart inoculation or an ongoing schedule of microbial top-ups.
Bacterial Habitats round out your prevention program. Along with oxygenation and microbial inoculation, support the potency of your beneficial bacteria population by giving it an environment to colonize. Beneficial bacteria requires a habitat in your pond for it to self-propagate, thus providing an uninterrupted force of healthy microbes to devour nutrients. Bacteria loves fine nooks and crannies to develop in, as you would find in a gravelly bed or a manufactured nesting site like BioBoost Nest.
The Long-Term Solution
When you see pesky aquatic weeds, think beyond the plants to the problem’s source – your pond’s nutrient load. By powering up nutrient-hungry beneficial bacteria with aeration, inoculation and habitats, you can win the war on weeds.