--- product_id: 707444220 title: "Kordon Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces" brand: "kordon" price: "49.18 DT" currency: TND in_stock: true reviews_count: 13 category: "Kordon" url: https://www.desertcart.tn/products/707444220-kordon-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater store_origin: TN region: Tunisia --- # Safe for fresh & saltwater 4 oz potent formula Prevents fungal & parasites Kordon Methylene Blue Disease Preventative – Safe for Freshwater & Saltwater Aquariums, Prevents Fungal Infections & Treats Parasites, Reduces Fish Stress, 4-Ounces **Brand:** kordon **Price:** 49.18 DT **Availability:** βœ… In Stock ## Summary > πŸ›‘οΈ Protect your aquatic world with Kordon’s trusted 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?** 49.18 DT with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/707444220-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 - β€’ **Dual Habitat Safe:** Formulated to work seamlessly in both freshwater and saltwater tanks. - β€’ **All-Age Aquarium Shield:** Effective for fish of every life stage, ensuring lifelong protection. - β€’ **Stress-Reducing Formula:** Calms your aquatic pets, promoting healthier, vibrant fish. - β€’ **Trusted American Quality:** Proudly made in the USA with rigorous quality standards. - β€’ **Comprehensive Disease Defense:** Prevents fungal infections and treats parasites for total tank wellness. ## Overview Kordon Methylene Blue is a 4-ounce, US-made aquarium treatment designed to prevent fungal infections and treat parasites in both freshwater and saltwater tanks. It reduces fish stress and is suitable for all fish ages, providing a reliable, quality-driven solution for maintaining a healthy aquatic environment. ## 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: My fish looks so much better and hes back to his old self - My betta was suffering from some kind of bacterial infection and I immediately ordered this because Ive heard great things. He's my first pet fish and I was especially worried when his energy started to decline and he wasnt his usual self. So when this came in the mail, I immediately set up a hospital tank and followed the instructions for dosage according to the tank size. I didnt notice a smell at all, but the water definitely turned deep blue. Its very pretty, but it will stain anything. My fish immediately started to perk up within the day. Within the next few days, he was acting normally and his fins even started filling out more. I recommend this absolutely!! Its easy enough to use, and safe for sick fish when used correctly. ## 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 | |---------------|-------| | ASIN | B00025646W | | Allergen Information | Odor-Free | | Best Sellers Rank | #6,930 in Pet Supplies ( See Top 100 in Pet Supplies ) #4 in Fish Medication & Health Supplies #42 in Aquarium Water Treatments | | Brand | Kordon | | Brand Name | Kordon | | Customer Reviews | 4.7 out of 5 stars 3,793 Reviews | | Global Trade Identification Number | 00048054373442 | | Included Components | KORDON #37344 Methylene Blue-General Disease Prevention Treatment for Aquarium, 4-Ounce, | | 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 | | Number of Packs | 1 | | Pet Type | Fish | | Target Species | Fish | | UPC | 048054373442 | | Unit Count | 4 Fluid Ounces | ## Product Details - **Brand:** Kordon - **Item Form:** Liquid - **Item Weight:** 4 ounces - **Liquid Volume:** 4 fluid ounces - **Number of Packs:** 1 ## 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) ## 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. ### ⭐⭐⭐⭐⭐ My fish looks so much better and hes back to his old self *by H***R on March 2, 2026* My betta was suffering from some kind of bacterial infection and I immediately ordered this because Ive heard great things. He's my first pet fish and I was especially worried when his energy started to decline and he wasnt his usual self. So when this came in the mail, I immediately set up a hospital tank and followed the instructions for dosage according to the tank size. I didnt notice a smell at all, but the water definitely turned deep blue. Its very pretty, but it will stain anything. My fish immediately started to perk up within the day. Within the next few days, he was acting normally and his fins even started filling out more. I recommend this absolutely!! Its easy enough to use, and safe for sick fish when used correctly. ### ⭐⭐⭐⭐⭐ Must have *by H***H on May 10, 2026* This was delivered extremely fast which was perfect as I had an axolotl with a fungus issue. This worked great as a bath and is really easy to use. I only needed a few drops and have almost the entire bottle left after treating my axolotl for about a week. This will stain your hands and your aquarium silicone if you have clear seals. I used this in a different tub for my axolotl. You only need a few drops per gallon to get the ideal water color for treatment. Definitely want to have this stuff on hand if you have aquariums! ## 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? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.tn/products/707444220-kordon-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater](https://www.desertcart.tn/products/707444220-kordon-methylene-blue-disease-preventative-safe-for-freshwater-and-saltwater) --- *Product available on Desertcart Tunisia* *Store origin: TN* *Last updated: 2026-09-03*