Hydra LT Extreme (Winter Bacteria)
Pack Size: 500gPack Size: 1 KgPack Size: 5 Kg
Pack Size: 2x5KgPack Size: 20 Kg

Hydra LT Extreme (Winter Bacteria)

Our Price  £25.96
List Price  £28.40
Saving Of  £2.44 (9%)
(Inc. 20% VAT)(£21.63 Exc. VAT)

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  (8 Reviews)
  • Psychrophile winter bacteria work at temperatures as low as 4°C
  • Unlike other bacteria it continues working during cold winter months
  • Reducing excess nutrients gives your pond or lake a head start in the Spring
  • Shelf life 3 years. For dilutions see below

Brand:  HYDRA



  • Blend of carefully selected pond beneficial bacteria strains that multiply rapidly to replace the bacteria lost during winters.
  • Nitrifying bacteria in LT Extreme act on harmful ammonia to convert it into nitrite and subsequently to nitrates.
  • The blend includes special beneficial bacteria that break down excess nutrients and organic matter to give clearer water.
  • Eliminates cloudy water and odour problems by acting upon pollutants and organic deposits in the pond.
  • Perfect for seeding new biological filters.
  • Gives your pond a head start by boosting the growth of beneficial bacteria.
  • Help maintain the ecological balance of the water.
  • Controls blanket weed and algae growth in the pond by digesting the nutrients required for their growth.
  • Easy to use, mix with pond water and add directly into the pond or filters.
  • Suitable to work efficiently in both freshwater and saltwater systems.
  • Safe to use in water with fish and aquatic plants.



In a balanced pond ecology, most types of good pond bacteria develop on their own, but often it is not sufficient to ward off common pond problems such as:

  • Cloudy water
  • Sludge accumulation
  • Bad odour from the slow decomposition of organic waste
  • Low pH level, i.e. increase in water acidity, harmful for fish and good bacteria
  • Depletion of dissolved oxygen levels


Pond keepers should maintain pond balance by adding bacteria in the pond, especially at the beginning of the winter season, when the good bacteria start to die out due to the cold temperature. LT Extreme includes highly concentrated beneficial bacteria (10 billion cfu/gram) that help resolve various water quality problems, including uncontrolled algae growth.

The blend includes a careful selection of different bacteria with various useful actions and qualities:

  • Ability to withstand a wide range of pH level and temperature
  • Ability to double every 20 minutes
  • Ability to digest specific nutrients that cause algae growth and poor water quality

LT Extreme is suitable for use with goldfish as well as koi fish ponds, boundary water courses, zoo ponds, leisure fishing lakes, and ecologically unbalanced ponds. The product gives excellent results in water bodies under intensive aquaculture operations such as livestock holding tanks, commercial fish farms, and angling clubs.


  • Switch off UV lights for 24 hours when first adding LT Extreme Bacteria to the system.
  •  If UV is part of the filter system then remove the fuse for the UV tube.



<1,000 litres (220 gallons) - 100gm

<2,000 litres (440 gallon) - 200g

<5,000 litres (1,100 gallon) - 300g

<20,000 litres (4,400 gallon) - 400g

<50,000 litres (11,000 gallon) - 500g

REPEAT MONTHLY from September - February. Can be used in summer months however for best results use Hydra Bio Aquatic Bacteria Boost.



Apply at 2 kilos per hectare each month or bi-monthly depending on the water quality and algae bloom. Higher dosages produce faster results.

REPEAT MONTHLY from September - February. Can be used in summer months however for best results use Hydra Bio Aquatic Bacteria Boost. 

How to Use

Treatment Rate Monthly: For Ponds

Apply at rates below. Repeat monthly from the beginning of October till March. For use when the temperature is below 12°C (54°F).

Size of Pond In Litres Size of Pond in Gallons Application
<1,000 litres 220 gallons 100 gram
<2,000 litres 440 gallons 200 gram
<5,000 litres 1,100 gallons 300 gram
<10,000 litres 2,200 gallons 350 gram
<20,000 litres 4,400 gallons 400 gram
<50,000 litres 11,000 gallons 500 gram



  • Apply at 1-2 kilo per acre each month or bi-monthly depending on the water quality and algae bloom.
  • Higher dosages of Hydra LT Extreme produce faster results.
  • Mix with pond water. Then, add directly to the water body. If possible circulate treated water by pump for even distribution.

Note: UV light is installed in the ponds to kill bacteria, however favourable bacteria also die out in the process. Therefore, to gain maximum benefit out of the product, please switch off the UV lights for at least 24 hours after adding LT Extreme in the water.

*Full Instructions on the label.

Average Rating (8 Reviews):  
Write a Review and share your opinions!

22 January 2020  | 

It has really helped my fish pond in the winter. Thank you


This review has not been appraised.

Winter treatment
15 November 2019  | 

My koi pond in winter needed treatment during cold weather. I added this monthly to keep the clarity of the water just right for my fish.


2 of 2 people found this review helpful.

Product works well
05 November 2019  | 

I saw a difference so quickly. My koi pond is looking good and healthy.


2 of 2 people found this review helpful.

Happy fish
10 February 2019  | 

Top stuff. Happy fish, and healthy waters.


This review has not been appraised.

Easy to use
04 December 2018  | 

This product is easy to use and really helped my pond out in the winter months.


2 of 2 people found this review helpful.

Thumbs up
29 October 2018  | 

I believe it has worked, I have had no problems to report after using.


This review has not been appraised.

Worked well
27 September 2018  | 

I added the treatment to my pond in winter and has worked really well.


1 of 1 people found this review helpful.

16 January 2018  | 

It has cleared up my pond water.


This review has not been appraised.