Pond & Lake Q & A
Q: The weather is getting colder, so can I still treat my pond with chemicals or natural bacteria? – Sara in Washington
A: Algae tends to grow all year long – even in cold temperatures when ice covers your pond. Given the right mix of nutrients, carbon dioxide and sunlight, these little photosynthetic, autotrophic compounds will flourish – regardless of the temperature or time of year.
Whether you can treat the pea soup or filamentous algae depends on the water temperature in your lake or farm pond. When the underwater thermometer drops below 50 degrees Fahrenheit, the effectiveness of both chemicals and natural bacteria begins to drop. So to get the most for your money, we recommend dosing your pond or lake with one of these methods in the fall before the winter chill hits:
- Treat with Chemicals: As long as your water temperature is about 50 to 60 degrees F, you can use algaecides, like Algae Defense® (or Hydrolthol 191 Granular if you have koi or goldfish in your pond), to help with late-season algae blooms. Warning: If your lake is stocked with trout, test your carbonate hardness before adding Algae Defense®. If your Water Hardness Test Kit reads less than 50 parts per million (2.79 degrees of hardness), it could be toxic.
- Add Some Shade: Regardless of your water temperature, you can also add pond dye to shade your pond or lake during the winter. Throughout the pond industry, experts use dye to minimize the amount of sunlight that reaches the depths of ponds and lakes. This can prevent algae from photosynthesizing – and limit its growth.
- Treat Naturally: Beneficial bacteria, like PondClear™ , are also most effective when temperatures are above 50 to 60 degrees F. When used correctly, they will help to keep your pond crystal clear.
POND TALK: Have you experienced a late-season algae bloom in your lake or pond? What did you do to control it?