--- product_id: 52326693 title: "Kordon Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces" brand: "kordon" price: "¥5900" currency: JPY in_stock: true reviews_count: 13 url: https://www.desertcart.jp/products/52326693-kordon-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater store_origin: JP region: Japan --- # Safe for eggs, fry & all fish types 4 oz potent liquid formula Fights fungal & protozoan infections Kordon Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces **Brand:** kordon **Price:** ¥5900 **Availability:** ✅ In Stock ## Summary > 🐠 Keep your aquarium thriving with Kordon’s blue shield! ## Quick Answers - **What is this?** Kordon 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?** ¥5900 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/52326693-kordon-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater) ## 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-Action Defense:** Prevents fungal growth and treats external protozoans like ich and costia. - • **Stress-Reducing Formula:** Supports fish vitality by reducing stress during treatment, promoting faster recovery. - • **Malachite Green Alternative:** Ideal for sensitive fish species, offering a safer, odor-free treatment option. - • **Aquarium-Safe for All Life Stages:** Gentle enough for fish eggs and fry, ensuring healthy aquatic generations. - • **Powerful 2.303% Methylene Blue Solution:** Clinically proven to combat fungal infections and parasites effectively. ## Overview Kordon Methylene Blue is a 4-ounce liquid treatment designed to prevent and treat superficial fungal infections and external parasites in freshwater and saltwater aquariums. Safe for fish eggs and fry, it serves as a reliable, odor-free alternative to malachite green, reducing fish stress while promoting a healthy aquatic environment. ## Description Product Description Methylene blue is effective against superficial fungal infections of fishes. The drug may be used as an alternative to malachite green for the control of fungus when it is known that the fish to be treated are sensitive. Methylene blue is safe for use with fish eggs and fry for the prevention of fungal infections. As a secondary use, it is effective against some external protozoans, such as ich, chilodonella and costia. Ingredients Methylene Blue is stable indefinitely in the 2.303% solution P.when('A').execute(function(A) { A.on('a:expander:toggle_description:toggle:collapse', function(data) { window.scroll(0, data.expander.$expander[0].offsetTop-100); }); }); Directions [GENERAL INSTRUCTIONS: Dilute and add the product to the aquarium water. Specific steps or dosage amounts are not provided in the given product information.] See more ## Features - Kordon methylene blue 4oz - Methylene blue is effective against superficial fungal infections of fishes - The drug may be used as an alternative to malachite green for the control of fungus ## Technical Specifications | Specification | Value | |---------------|-------| | Allergen Information | Odor-Free | | Asin | B00025646W | | Best Sellers Rank | 45,117 in Pet Supplies (See Top 100 in Pet Supplies) 477 in Aquarium Water Treatments | | Brand Name | Kordon | | Country Of Origin | USA | | Customer Reviews | 4.7 4.7 out of 5 stars (3,659) 4.7 out of 5 stars | | Global Trade Identification Number | 00048054373442 | | Included Components | BOTTLE, CAP | | Item Form | Liquid | | Item Type Name | KORDON # 37344 METHYLENE BLUE 4 OZ. | | Item Weight | 4 Ounces | | Liquid Volume | 4 Fluid Ounces | | Manufacturer | KORDON LLC | | Manufacturer Part Number | 048054373442 | | Model Number | MODEL-37344 | | Number Of Items | 1 | | Pet Type | Fish | | Target Species | Fish | | Unit Count | 118.0 millilitre | | Upc | 048054373442 | ## Product Details - **Brand:** Kordon - **Item form:** Liquid - **Item weight:** 4 Ounces - **Liquid volume:** 4 Fluid Ounces - **Manufacturer:** KORDON LLC ## Images ![Kordon 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) ## 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 ### ⭐⭐⭐⭐⭐ Good product *by on Reviewed in the United Kingdom 1 November 2025* Works well great stuff ### ⭐⭐⭐⭐⭐ Medicine staple for fish keepers *by on Reviewed in the United Kingdom 9 September 2025* This product works really well. As someone who breeds fish and also keeps Axolotls I have used this multiple times and has always done its job. Used it for preventing fungus on eggs as well as treating fungus on Axolotls gills ### ⭐⭐⭐⭐⭐ Perfect *by on Reviewed in the United Kingdom 6 September 2025* Great product ## 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 --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.jp/products/52326693-kordon-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater](https://www.desertcart.jp/products/52326693-kordon-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-08-22*