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Koi Care - Zeolite with Filter Media Bag

Zeolite 2

Rapid Ammonia Removal

  • Filter Bag Included.
  • Also reduces toxic Nitrite and Nitrate levels.
  • Maintains the health and vitality of your fish.
  • Large 10-35 mm chunks.
  • Ideal for large filters.
  • Can be re-charged.
  • Can be used for decorative effect in the pond.

When to Use:

  • For best results, use throughout the year and recharge regularly.
  • Recharge and top up when water quality begins to fall.


  • Place into the filter bag provided and rinse under the tap.
  • Place in the filter in an area with a strong flow of water.
  • Test your water quality using Pondlab Test Kits.
  • Recharge in spring and every 6 weeks (unless poor water quality is detected). Replace 50% of the zeolite with every recharge.
  • To recharge: prepare a salt solution (4 tablespoonsper gallon of water) and soak the chunks for 24 hours.

Test your water quality first using Pondlab test kits.

For common frequently asked questions, click here.



Available in the following variations:


Where to Buy?

Simplified map of the United Kingdom.


Let us calculate your dosage for you!

To make the process of using our products even easier this handy dosage calculator tells you the amount you will need to put into your system. Please ensure you also read the instructions and warnings that are written on the bottle/pack label.

I know my system's measurements and want to:

Calculate my volume
Dosage calculator

Calculate dosage

You’ll require*
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* Always follow the instructions on the label. This calculator is intended to be used only as a guide to how much product you need to buy to treat your system. It does not take account of displacement caused by gravel, rocks and ornaments etc and does not include the volume of any external filtration system. NT Laboratories Ltd. will not accept any responsibility for inaccuracies or misuse of this guide.

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  • Keith Holmes - Koi Waterbarn from Knockholt, Sevenoaks

    Koi Water Barn and NT Labs have a long history of working together, we feel that the products in the Koi Care range offer our customers a quality product at a realistic price. This is backed up by extensive research and development that is carried out at the NT Labs HQ located in Kent. They are not far away from our shop at Coolings (Knockholt, near Sevenoaks), this is an added bonus for our customers as they are buying from a local UK based company.