Order before 1pm for next working day delivery Learn more

FREE delivery on orders over £49* Learn more

Celebrating 60 years and still family run

Product code: 221

NT Labs Koi Care Formaldehyde

Regular price £1299

Bottle size

£12.99
£11.04

Auto-renews, skip or cancel anytime.

£19.99
£16.99

Auto-renews, skip or cancel anytime.

£29.99
£25.49

Auto-renews, skip or cancel anytime.

£49.99
£42.49

Auto-renews, skip or cancel anytime.

To add to cart, go to the product page and select a purchase option

Order before 1pm for next working day delivery


If your fish display signs of parasitic infection such as white spots on their fins and body, frequent flicking and rubbing, gasping at the water surface, or a cloudy film covering their body, NT Labs Koi Care Formaldehyde is the effective solution to help restore their health.

Formaldehyde is highly effective at treating parasites due to its ability to penetrate through the mucus layer, reaching those parasites which would otherwise be protected from alternative bath treatments. It can also be used in conjunction with Malachite to treat protozoan parasites more effectively.

How to use?

  • Test your water quality using NT Labs Test Kits.
  • Mix the appropriate dosage in a clean bucket of pond water, pour evenly over the surface of the pond and leave for 7 days. Switch off UV filtration for 5 days. Aerate the pond well during treatment.
  • If you feel a repeat dose is necessary, check your diagnosis carefully using the Diagnosis Tool; a different medication may be more suitable. Allow 7 days and perform a partial water change before re-treating or treating with a different medication.
  • Always treat when you have time to observe fish and take appropriate action in the unlikely event of a bad reaction.
  • If required, mix with Malachite prior to adding to the pond, following the instructions above.

Warning:
Do not use with orfe, rudd, tench or sturgeon/sterlet.
Do not use if the water temperature is above 30°C.
Do not use in hot, humid, thundery conditions.
Do not mix medications, other than combining with Malachite.

Delivery

We offer free DPD next working day delivery to all UK mainland online orders over £49. For orders under £49, a flat fee of £5.99 applies.

For orders to the Channel Islands, Isle of Man, Scottish Highlands, and Scilly Isles, DPD provides a two-working day delivery service, and additional shipping charges may apply at checkout.

Please note: We currently do not ship to Northern Ireland.

Selected items that are not available to order online may be available for local delivery at an extra charge.

Orders placed before 1pm Monday to Friday are dispatched the same day, subject to stock availability.

Click & Collect

We offer free store collection at our Wirral store, with orders ready for collection in as little as 15 minutes, depending on stock availability. If the item is not available at the Wirral store, you can choose to place the order on hold till stock arrives.

Please note that your order will be held for 7 days. Any orders not collected within this period will be automatically cancelled and refunded in full.

Returns & Refunds

We offer a FREE 60-day returns policy. To start your return, simply give us a call on 0151 336 3616 or initiate your return through our returns portal

For our full returns policy click here

Need advice?

Call and speak to a human expert on 0151 336 3616

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.