Description
Suitable for coldwater & tropical aquariums. Treatment for bacterial, fungal, and some external protozoan parasitic infections of fish, fry, and eggs.
When to Use:
- When fish, fry, or eggs show signs of fungal infections such as fluffy cotton wool-like growths. If fish have grey, velvety film over their body or have excess mucus. If fish have red open wounds, ulcers, missing scales, rotting fins, or eroded mouth tissue.
- Methylene Blue can be used to treat bacterial, fungal, and some external protozoan parasitic infections. It is safe for use with eggs and fry. It is best used in a quarantine aquarium or treatment bath but can be added to the aquarium water, when transporting fish, or applied directly to wounds.
Warning:
- This product may kill live plants and shrimp if overdosed.
- This product will affect beneficial bacteria in the biofilter.
- This product can stain skin, aquarium ornaments, and silicone.
- Continue filtration during treatment but remove carbon. Carry out a 25% water change after finishing treatment, add NT Labs Filter Starter to the aquarium, and reapply carbon to the filter.
- If applying directly to wounds, dab undiluted Methylene Blue on affected areas using a cotton bud.
How to Use:
- Calculate the volume of your aquarium in litres (length x width x depth (in cm)/1000). Alternatively visit: www.nt-labs.com/dosage-calculator and we will calculate it for you!
- Shake bottle thoroughly before use.
- Mix required dose of treatment with 1 litre of aquarium water. Add slowly to aquarium.
- For a dip dose, see the label for the correct dosage rate.
- Treatment can be repeated 4 days after last dose. If you feel a second dose is required, first check your diagnosis is correct, test your water quality using NT Labs Test Kits and carry out a 30% partial water change.

Whether you’re collecting from our store, ordering dry goods, arranging local delivery or having livestock delivered nationwide, we’ve made it simple to choose the right option.
Click & Collect
FREE COLLECTION FROM OUR STORE
Place your order online and select Click & Collect at checkout.
Livestock will normally be bagged when you arrive, helping to minimise the amount of time animals spend packaged. If you’d prefer your livestock to be ready beforehand, simply contact us in advance.
Local Delivery
DELIVERED BY TROPICAL SUPPLIES • WITHIN 25 MILES
Order from our in-store range and have it delivered directly to you using our own local delivery service.
Minimum order: £50
Local Delivery Charges:
Up to 5 miles — FREE
5–10 miles — £10
10–15 miles — £15
15–20 miles — £20
20–25 miles — £25
Distances are measured “as the crow flies” rather than by road.
Once your order has been placed, we’ll contact you to arrange a suitable delivery date and time. We often combine nearby orders into efficient delivery runs, so local delivery may take a little longer during busy periods.
Ordering a large aquarium?
Please make sure someone is available to help unload the aquarium from our van when we arrive.
Dry Goods Delivery
DX Express
0–75kg • Usually 1 working day
Orders placed before 12 noon may be dispatched the same day on our current dispatch days.
Express Pallet
75–500kg • Usually 1–3 working days
Designed for larger and heavier orders that cannot be sent using our standard parcel service.
Please note: We currently dispatch parcels Wednesday to Friday.
Adding Something to an Existing Order?
If your original order hasn’t been dispatched yet, simply place the additional items as a Click & Collect order and leave us a note asking us to combine them with your existing order.
Available to Order
See something you want that we don’t currently have on the shelf? Many of our products can be quickly sourced from our suppliers.
Products marked Available to Order are not currently held in stock at our store but are available for us to order on your behalf.
Most items arrive with us within a few days and usually no longer than a week, depending on supplier availability.
Once your item arrives with us, we’ll either dispatch your order or let you know it’s ready for collection, depending on the delivery option you selected.
After receiving your order, we’ll check availability with our supplier. If there are any issues or expected delays, we’ll contact you to let you know.
Nationwide Livestock Delivery
Have your new livestock delivered safely to your door using our specialist livestock delivery service.
Minimum livestock order: £50
Thursday Delivery — £24
Order by: Wednesday, 12 noon
Dispatched: Wednesday afternoon
Delivered: Thursday before 1pm
Friday Delivery — £24
Order by: Thursday, 12 noon
Dispatched: Thursday afternoon
Delivered: Friday before 1pm
Saturday Delivery — £29
Order by: Friday, 12 noon
Dispatched: Friday afternoon
Delivered: Saturday before 1pm
Add Dry Goods to Your Livestock Order
You can include dry goods with your livestock delivery, making it easy to top up food, treatments, equipment and other supplies at the same time.
Please note: Frozen food cannot be shipped with livestock and must be ordered separately.
Already Placed Your Order?
No problem. If your livestock order hasn’t been dispatched yet, place another order using Click & Collect and leave us a note asking us to combine it with your existing order.
Payment & Security
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
