---
product_id: 707444220
title: "Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces"
brand: "kordon"
price: "A$44"
currency: AUD
in_stock: true
reviews_count: 8
url: https://www.desertcart.com.au/products/707444220-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater-aquariums
store_origin: AU
region: Australia
---

# Safe for fresh & saltwater 4 fl oz potent liquid Prevents fungus & parasites Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces

**Brand:** kordon
**Price:** A$44
**Availability:** ✅ In Stock

## Summary

> 🛡️ Keep your aquatic friends thriving with Kordon’s blue power!

## Quick Answers

- **What is this?** Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces by kordon
- **How much does it cost?** A$44 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.au](https://www.desertcart.com.au/products/707444220-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater-aquariums)

## Best For

- kordon enthusiasts

## Why This Product

- Trusted kordon brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Dual Habitat Safe:** Perfectly formulated for both freshwater and saltwater tanks
- • **Versatile Use Case:** Treats fungal infections, parasites, and boosts oxygen for stressed fish
- • **All-Age Aquarium Shield:** Effective disease prevention for fish of every stage
- • **Stress-Reducing Formula:** Calms fish during treatment, minimizing stress reactions
- • **Trusted American Quality:** Proudly made in the USA with rigorous safety standards

## Overview

Kordon Methylene Blue is a 4-ounce liquid treatment designed to prevent fungal infections and treat parasites in both freshwater and saltwater aquariums. Made in the USA, it also reduces fish stress and supports oxygenation, making it an essential, safe, and versatile solution for maintaining healthy aquatic environments.

## Description

KORDON #37344 Methylene Blue-General Disease Prevention Treatment for Aquarium, 4-Ounce,

Review: Fungus, not sure what's going on. Fish need extra oxygen. - I've been using methylene blue for a long time. I use it for fungus on my fish if I notice a little bit starting or if their coat starts getting a little slimy. I usually try this before I try anything else. Or if for some reason my nitrates or nitrite spike I'll use this a little bit for some added oxygen if my fish start getting stressed out or are already stressed out. This has always worked very well for me. I've never had any fish stressed out about it. No headshaking ever like what happens when I add metronidazole or praziquantal or other meds. Methylene blue has also never hurt my pond plants. I don't pour it directly in my pond. It's always been in the hospital tank. I did recently use it when I bought some water hyacinth from a pond shop. I always bring them home and put them in a container with grow lights and heat to make sure that they don't have a bunch of snails and dragonfly nymphs and whatever else there is on those things. Well, I ended up having a bunch of baby fry fish hatch from these plants. About a week later the little fry baby's started turning white and dying. I wasn't really sure what to due because I didn't want to kill these plants that I just spent a couple hundred dollars for and I didn't want to let the baby fish die. I added some methylene blue and some nitrofuranzone together with the baby fry and with the plants which also had snails, snail eggs, dragonfly nymphs on them and the white that I guess was fungus on these little baby fish I can't really tell because they were so small. I did it once left it in there for two days and then the partial water change and I didn't have any more baby fry fish die and my Hyacinth plants are still growing and still blooming. Some even flowered out purple flowers right away. So it didn't hurt them at all. I was kind of disappointed about these plants and there had to have been something on them for these baby fish to get this but not only that the guy told me that they had goldfish in with the plants. I called And asked him after all these baby fries start hatching. I think something that people should think about, and I don't know if people actually just buy plants and throw them in their ponds. I always did and I always ended up coming down with some kind of ailment around that time and I just thought it was a change in temperature, water parameters. But if the place where you buy the plants has goldfish or other fish in with them they have a fungus or bacterial infection and you bring those plants home and throw them in your pond you're going to bring that stuff into your pond. So for now on I quarantine my plants. Back to the methylene blue. It's definitely blue. I've never had it stain anything. I took pictures of what it looked like. It took pictures of my fingers after completely just dipping them in the stuff. And then the last picture I took was me washing my hands one time. It was almost completely off. Once I take a shower it's completely gone. I've never had the methylene blue stain anything that I've ever had permanently. I think that having the methylene blue around in case you have something going on and you don't know what it is is a fish lifesaver. You can at least be able to use it just in case you need to. It is better than not having anything at all. If I wouldn't have had the methylene blue on hand along with the nitrfurazone at the time I'm pretty sure all the little fish would have been dead. Because that morning when I checked on them they had nothing white on them. Later that afternoon is when I started noticing it. About four of them died. So that's my methylene blue story. I'm not sure how it would stain if you got it like on your rings or your jewelry or anything but it does eventually go away when I get it on my hands and stuff.
Review: Saved my betta - Saved my betta from dropsy. This stuff is a life saver. It is very safe as long as you dose correctly. And my betta is happy and healthy now because of it!

## Features

- 100% Quality driven Made in the USA
- Dedicated to creating a better environment for your pet
- Safety Guaranteed, Don't settle for Less, Use Kordon
- AQ MEDICATIONS & REMEDIES, FW
- Age Range Description: All Ages
- Package Dimension : 1.27 centimeters L x 2.286 centimeters W x 12.954 centimeters H
- Item Package weight : 0.136 kilograms

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | Kordon |
| Customer Reviews | 4.7 out of 5 stars 3,708 Reviews |
| Item Form | Liquid |
| Item Weight | 4 Ounces |
| Liquid Volume | 4 Fluid Ounces |
| Manufacturer | KORDON LLC |
| Pet Type | Fish |

## Product Details

- **Brand:** Kordon
- **Item Form:** Liquid
- **Item Weight:** 0.02 Pounds
- **Liquid Volume:** 4 Fluid Ounces
- **Manufacturer:** KORDON LLC

## Images

![Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces - Image 1](https://m.media-amazon.com/images/I/61Ueqt3BcYL.jpg)

## Available Options

This product comes in different **Pattern, Size** options.

## Questions & Answers

**Q: Has anyone used this for fin rot and does it work well?**
A: Use a few drops of this with a tsp of Epson salt per gallon and your fishy will heal. The methylene blue will stick to wound to provide oxygen to promote healing. Change 1/3 of the water per week.

**Q: Is this solution good for microscope labs?**
A: heck yeah!

**Q: Can someone tell me if there are any additional ingredients ( preservatives,food colorings,additives,etc.) in this product?**
A: label does not list any addl ingredients. Does state for aquarium fish use only. Not for human or food fish use.

**Q: How much do you use per gal?**
A: Please aquarium use, please follow the directions on the bottle, which says 1 tsp in 10 gallons produces a 3ppm solution. For 1 gallon, one tenth of a teaspoon is 0.5 mL, or about 10 drops. For other uses, please be aware that this is not a 1% solution. The manufacturer states that this is a 2.303% solution. This means that each drop contains 1.15mg (not 0.5mg).

## Customer Reviews

### ⭐⭐⭐⭐⭐ Fungus, not sure what's going on. Fish need extra oxygen.
*by T***N on May 21, 2020*

I've been using methylene blue for a long time. I use it for fungus on my fish if I notice a little bit starting or if their coat starts getting a little slimy. I usually try this before I try anything else. Or if for some reason my nitrates or nitrite spike I'll use this a little bit for some added oxygen if my fish start getting stressed out or are already stressed out. This has always worked very well for me. I've never had any fish stressed out about it. No headshaking ever like what happens when I add metronidazole or praziquantal or other meds. Methylene blue has also never hurt my pond plants. I don't pour it directly in my pond. It's always been in the hospital tank. I did recently use it when I bought some water hyacinth from a pond shop. I always bring them home and put them in a container with grow lights and heat to make sure that they don't have a bunch of snails and dragonfly nymphs and whatever else there is on those things. Well, I ended up having a bunch of baby fry fish hatch from these plants. About a week later the little fry baby's started turning white and dying. I wasn't really sure what to due because I didn't want to kill these plants that I just spent a couple hundred dollars for and I didn't want to let the baby fish die. I added some methylene blue and some nitrofuranzone together with the baby fry and with the plants which also had snails, snail eggs, dragonfly nymphs on them and the white that I guess was fungus on these little baby fish I can't really tell because they were so small. I did it once left it in there for two days and then the partial water change and I didn't have any more baby fry fish die and my Hyacinth plants are still growing and still blooming. Some even flowered out purple flowers right away. So it didn't hurt them at all. I was kind of disappointed about these plants and there had to have been something on them for these baby fish to get this but not only that the guy told me that they had goldfish in with the plants. I called And asked him after all these baby fries start hatching. I think something that people should think about, and I don't know if people actually just buy plants and throw them in their ponds. I always did and I always ended up coming down with some kind of ailment around that time and I just thought it was a change in temperature, water parameters. But if the place where you buy the plants has goldfish or other fish in with them they have a fungus or bacterial infection and you bring those plants home and throw them in your pond you're going to bring that stuff into your pond. So for now on I quarantine my plants. Back to the methylene blue. It's definitely blue. I've never had it stain anything. I took pictures of what it looked like. It took pictures of my fingers after completely just dipping them in the stuff. And then the last picture I took was me washing my hands one time. It was almost completely off. Once I take a shower it's completely gone. I've never had the methylene blue stain anything that I've ever had permanently. I think that having the methylene blue around in case you have something going on and you don't know what it is is a fish lifesaver. You can at least be able to use it just in case you need to. It is better than not having anything at all. If I wouldn't have had the methylene blue on hand along with the nitrfurazone at the time I'm pretty sure all the little fish would have been dead. Because that morning when I checked on them they had nothing white on them. Later that afternoon is when I started noticing it. About four of them died. So that's my methylene blue story. I'm not sure how it would stain if you got it like on your rings or your jewelry or anything but it does eventually go away when I get it on my hands and stuff.

### ⭐⭐⭐⭐⭐ Saved my betta
*by K***D on November 30, 2025*

Saved my betta from dropsy. This stuff is a life saver. It is very safe as long as you dose correctly. And my betta is happy and healthy now because of it!

### ⭐⭐⭐⭐⭐ Great Medicine for my Freshwater Fish
*by K***N on October 5, 2025*

Worked great on my sick fish, kept the fish in the Methylene Blue for a few days and slowly started to do water change to ease it's transition back into normal water. Just follow the instructions and be careful not to spill as it can stain counter tops.

## Frequently Bought Together

- Kordon Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces
- Kanaplex, 5 g(0.18 oz)
- API AQUARIUM SALT Freshwater Aquarium Salt 36-Ounce Box

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*Product available on Desertcart Australia*
*Store origin: AU*
*Last updated: 2026-03-11*