Follow the below steps for the greatest chance of eradicating submerged aquatic weeds from your dam for good
Step 1
Manually remove as much of the submerged weed as possible
Before treatment it is important to remove as much weed as possible using one of the methods below. If you're struggling to see where your weeds are most concentrated, use an eco-friendly dam dye to darken the water so you can better see the plants.
Beachroller
For soft-celled plants: Beachroller features a 3-blade design that rolls along the floor of your dam, cutting and ripping up weeds. The tool also tills the soil which slows regrowth.
Aquatic Weed Hand Cutter
For hardier plants: The Aquatic Weed Hand Cutter is a high quality, comfortable-to-use tool that makes short work of submerged weeds. For deeper areas, we recommend duct taping the cutter to a pool net extension pole.
Lake Bottom Blanket
For spot treatments: Lake Bottom Blankets kill aquatic weeds by blocking their access to sunlight. This starves them to death because they can’t photosynthesise food.
Step 2
Increase aeration
Aeration means adding oxygen to your water. This provides ideal conditions for “good” aerobic bacteria to grow in number. These “good” guys reduce nutrients in your dam, e.g. nitrogen and phosphorus, and eat sludge on the floor which is fertiliser for aquatic weeds. With enough “good” bacteria reducing nutrients in your dam, new or regrowing weeds find it difficult to survive.
How does aeration improve water quality
Eradicating azolla and blue-green algae in 6 weeks with a surface aerator
Avalon Nursery near Ballarat was having a problem with red azolla and blue-green algae in one of their irrigation dams.
We recommended installing a 1.5hp solar-powered Air-O-Lator Carnival Aerating Fountain. Within days of installing the aerator, the azolla and blue-green algae began to retreat. After just 6 weeks, the weed and algae were completely gone. The smell had disappeared too.
Step 3
Add Biostim probiotics
Biostim is a probiotic that feeds the “good” bacteria in your dam, growing their populations. As mentioned above, these guys consume nutrients like nitrogen and phosphorus and eat the sludge on the floor of your dam. Eventually they create (nutrient-depleted) conditions that makes it tough for aquatic weeds to grow, no matter how much sunshine your dam receives. There simply isn't enough food to go around.
How does Biostim improve water quality?
In extreme cases, take Step 4 to kill your aquatic weeds immediately.
We typically don’t encourage use of herbicides because they're not selective in keeping the "good" plants while killing the "bad". But in extreme cases, you may have no choice. In this situation, we recommend you follow the instructions below.
Step 4
Herbicide (+ Biostim Accelerator)
If killing your aquatic weed immediately is your only option, we suggest you use an herbicide (our recommendation is WaterTreats Aquatic Weed Killer or Knockout Aquatic Herbicide) in combination with Biostim Accelerator. Biostim Accelerator is a 100% natural biocatalyst which improves the effectiveness of herbicides, reducing how much you need to use.
How Biostim Accelerator works
Biostim Accelerator
WaterTreats Aquatic Weed Killer
Knockout 360 Aquatic Herbicide
Remember, you must combine herbicide use with Step 2 and 3 if you want to prevent aquatic weeds from returning. The reason is if you don’t improve numbers of “good” bacteria by aeration and Biostim then you’re leaving the food supply in the water which the next generation of weed or algae can use. They simply take the place of what you’ve just killed. This leads to a chemical cycle of needing to continually kill the next generation of weed. Over time this can really impact the health of your dam.
