Winter Pond Care: Nutrient Removal and Algae Treatment

Clean water means removing excess nutrients — in other words, pollution. In winter, the target is phosphorus, because troublesome algae, especially the kind that grows in cold water, depends on it.

Why phosphorus?

Even small amounts of phosphorus can fuel large amounts of algal growth, clouding the water, reducing its recreational value and stressing fish and other aquatic life. Because phosphorus is often the limiting nutrient in fresh water, reducing it goes straight at the root cause of many algae and clarity problems.

Take out the phosphorus

We use two phosphorus binders that work directly in the water column:

• PhosClear is a buffered aluminum sulfate (alum) granule that removes phosphate and clarifies turbid water. It is applied by broadcasting the granules or as a slurry.
• EutroSORB WC is a ready-to-use liquid blend of phosphate-binding minerals that rapidly and permanently inactivates phosphorus. It can be sprayed on the surface, injected below it or poured into well-mixed areas, with minimal impact on water chemistry.

Which one is right depends on your water chemistry and goals. See our phosphorus reduction recommendations for how each works.

Add a monthly diatom promoter

During winter months, when the water is not frozen, you can also treat monthly with Aquaritin. It encourages native diatoms to take up nitrogen and phosphorus and to add oxygen to your pond or lake, without chemicals, dyes or bacteria.

Keep the oxygen moving

Aeration helps a pond through the cold months too. Bottom-diffused aeration supports year-round oxygenation, including under ice, in deeper water. Our aeration guide compares the options.

Dosing at no charge

Proper dosing for any nutrient-removal supply is provided at no charge by our charity’s scientists, so you can treat with confidence.

As always, we are glad to discuss your specific pond. Contact us or call Matt at 571-436-6327. Here’s to cleaner surface waters through nature-based solutions!