Protect Your Fish from Invisible Winter Ammonia Build-Up

WinterGard keeps biological filtration working in cold water — so toxic forms of ammonia don’t quietly accumulate under the ice. 

You can’t see it from the surface, but as muck and other organic waste continues to break down over winter, they release ammonia into a system where warm-water bacteria have largely shut down. Our field tests show how quickly these winter chemistry shifts can stress fish.  WinterGard was formulated to answer that: a cold-water bacteria blend that stays active between 38–60°F, helping convert ammonia and support a safer environment for your fish until spring.

Why WinterGard Matters in Cold Water

• Helps control toxic ammonia all winter
  As organics decompose, WinterGard’s cold-water bacteria help convert toxic, un-ionized ammonia into less harmful forms — even when warm-water strains have slowed down.

• Keeps organic waste breaking down in cold temps
  Supports ongoing breakdown of leaves, fish waste, and other organics so winter loading doesn’t overwhelm your pond biology.

• Supports more stable winter water chemistry
  Helps reduce sudden shifts in ammonia and nutrients that can stress fish under ice or in low-circulation conditions.

• Helps fish come through winter stronger
  Less ammonia stress means healthier gills, better immunity, and fewer unexplained winter losses.

• Simple, safe, and natural
  Toss-in dosing every 1–2 weeks. Beneficial bacteria only — safe for fish, pets, wildlife, and your existing aeration system

Check our Realtime Surface Water Temperature Map to see if it's time to treat with WinterGard

Treat with WinterGard while leaves and dying vegetation accumulate in fall and winter months. Leaves and dead vegetation turn to muck which create water quality issues. WinterGard protects your pond from winter water issues that arise from increasing nutrient levels.

Ideal for use in ponds as temperatures drop in Fall and in early Spring before water temperature reaches 60 degrees. The blend of winter bacteria and enzymes produce optimal results during cooler months.

10 lb pail treats 0.25 acre pond for 5 months

Includes 20 water soluble packets that weigh 0.5 lbs each

 WinterGard Treatment Instructions:

Water soluble packets dissolve quickly in water. Simply toss packets into pond every 2 weeks.

Apply 2 packets per 1/4 acre. Apply 8 packets per 1 acre pond. 

Pond treatment safe for fish, wildlife, and recreational use immediately after application.

What is WinterGard?

Special blend of cold water bacteria, enzymes, and stimulants in water soluble packets

What makes this pond treatment special?

This formula hits peak performance when water temperature drops in fall and winter. 

What does WinterGard do?

It protects the pond and fish from winter water quality issues like rising nutrients and accumulating waste. These issues trigger algae blooms, reduce clarity, and decrease oxygen levels.

Boost results by combining WinterGard with Pondzilla Pro.

While WinterGard is reducing nutrients and organics, Pondzilla accelerates the breakdown time of new leaves falling into the pond. Over time leaves break down into muck which is consumed by bacteria like WinterGard. Adding Pondzilla to your fall treatment schedule reduces the time it takes for leaves to turn to muck and then be consumed by pond bacteria.

When to use WinterGard with Pondzilla

Use both products anytime water is below 60 degrees and there is an abundance of leaf build up.

Safe to apply WinterGard and Pondzilla at the same time

Fall Pond Treatment Combo Instructions

1. Toss recommended number of WinterGard Packets into pond
2. Mix recommended volume of Pondzilla with water and spray in areas where leaves accumulate
3. Repeat application every 2 weeks