--- product_id: 5951852 title: "Seachem Flourish Potassium 250ml" brand: "seachem" price: "£8.27" currency: GBP in_stock: true reviews_count: 12 url: https://www.desertcart.co.uk/products/5951852-seachem-flourish-potassium-250ml store_origin: GB region: United Kingdom --- # Phosphate & nitrate free formula 50,000 mg/L potassium concentration Compact 250ml liquid dosing Seachem Flourish Potassium 250ml **Brand:** seachem **Price:** £8.27 **Availability:** ✅ In Stock ## Summary > 🌿 Unlock your aquarium’s green potential with every drop! ## Quick Answers - **What is this?** Seachem Flourish Potassium 250ml by seachem - **How much does it cost?** £8.27 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/5951852-seachem-flourish-potassium-250ml) ## Best For - seachem enthusiasts ## Why This Product - Trusted seachem brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Precision Dosing:** Compact 250ml liquid form allows easy, controlled supplementation for any planted aquarium size. - • **Clean & Pure Formula:** Zero phosphate and nitrate content means no unwanted algae triggers—just pure plant nutrition. - • **Maximize Plant Growth:** Delivers a potent 50,000 mg/L potassium boost to fuel lush, vibrant aquatic plants. - • **Algae Defense Strategy:** Feeds plants faster than algae can compete, naturally reducing algae outbreaks and keeping your tank pristine. - • **Synergistic Ecosystem Support:** Designed to work seamlessly with the full Seachem Flourish line and Fluorite gravel for optimal plant health. ## Overview Seachem Flourish Potassium is a high-concentration liquid potassium supplement (50,000 mg/L) formulated specifically for freshwater planted aquariums. It supports vigorous plant growth by preventing potassium depletion without introducing phosphate or nitrate, which can fuel algae. Ideal for use alongside the full Flourish product line and Fluorite gravel, this 250ml bottle offers precise dosing to maintain a thriving, algae-resistant aquatic environment. ## Description Sachem Flourish Potassium contains 50,000 mg/L of potassium suitable for the natural freshwater aquarium. Potassium is one of several elements that are vitally important to maintaining a vigorous level of growth in a planted aquarium. Potassium can become depleted in a rapidly growing system or when the source water has a low mineral content. In these cases potassium could become the limiting factor to growth. Use Flourish Potassium to prevent potassium depletion and maintain the highest level of growth. Flourish Potassium is an integral component of Sachem's plant products and is recommended for use with the entire Flourish line as well as our Fluorite gravel. Contains no phosphate or nitrate. Review: Great, little goes a long way, effective - I use a little less than half recommended bottle dosage every day of all seachem ferts (rotate days between trace and flourish complete). Also use online co2 calculator and use just below dose of co2 tank from 5 am to 5pm. Then I air stone at night. Slightly underused recommended fish food once or twice a day. I take no days off. 2/3rd water change and vacuum every 10 days. Perfect numbers and very slow minimal acceptable algae growth on walls to be hardly visibly noticeable. I created my own HOB power filter and pre-filter using a number of materials from desertcart sources. I only clean the sponges and not the physical media, squeeze them out in the throw out water that comes out during water change. Aquarium maintenance 101 from a newbie. Use as little substrate as possible to keep plants alive to more easily avoid snails. Clean literally everything before putting into aquarium, better for it to die before going in aquarium than to introduce snails. Scrape the walls of algae at each waterchange. If you get snails, take literally everything out but fish and inverts, and soak it in a low ratio bleach plus water bath for like 20 minutes, this is the only way to kill all pest snails literally. Drain the water to just enough for the fish and inverts to swim and live, then scrub the entire aquarium with a scraper and take out literally anything you can see. Scrape again 3 times. Wipe it all down and make sure all there is you can see is the fish and inverts and clear water. Then wipe again. Add plenty of cycling bacteria from multiple sources you can find on desertcart including seachem. Refill the aquarium with the bleach soaked plants decorations subtrate and filter medias. MAKE SURE YOU SOAK IN PLENTY OF DECHLORINATOR AND WATER FOR 20 MINUTES first. None of your plants should die off completely but they will lose and have killed a good amount of their leaves and roots but they should survive and regrow if you fert and change new water and quick cycle with added bacteria I truly hope this helps. My first year with a fully stocked nano tank has been a lot of time reading and experimenting. The pest snail battle was epic but I've been free for 6 months completely. I win. Oh and didn't lose a fish or invert and plants are beyond original growth. This is with having done zero quarantining or adapting at any point. I also cycled from day one, no precycling. Use a 24 hour light with cycling phases and full K spectrum for plants. It is way easier and effective and worth the minor price increase over standard lights. And it is fun Also add Indian leaves and a UV filter Filter floss = crystal clear water. Chemical filtration is entirely unnecessary Have had no issues and made zero adjustments in six months everything has been clear and clean, green growth strong, living things have thrived. Electric heater w built in temperature control at 82 degrees for tropical fish and plants Review: Very powerful product for all planted aquariums - Seachem products are very helpful and essential to planted fish tanks for a variety of reasons. If you are just beginning to venture into a live planted aquarium, these are great products to dose. With that being said, you do have to use caution to not over do it. If you are researching this product, let me tell you why and how they work to help you make up your mind: 1. Using the proper doses of seachem products together help your plants grow firm, tall, and gain the beautiful glow they need. 2. Natural algae block!!! A common problem in planted aquariums is algae. Proper dosage of these products provide your plants with nutrients that are designed to be readily absorbed by your plants before algae can get it. Plants and algae compete in the aquarium for nutrients and proper use of seachem products will give your plants a jump start to suck up the nutrients before algae will get to it and grow. 3. Plants are a great natural filter for your aquarium and if you have fish that breed, the rapid growth will allow your fish great coverage and hiding areas to either lay eggs or have their babies. The list goes on and on about why these products do work well, but you have to remember to get everything together for a good planted aquarium to work. Seachem is wonderful enough to provide dosing regimens on their website. I successfully used it as a guide and tweaked it to what my plants needed. ## Features - Potassium supplement - For planted aquariums - Contains no phosphate or nitrate ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0002A5WRY | | ASIN | B0002A5WRY | | Allergen Information | Yam Free | | Best Sellers Rank | #10,547 in Pet Supplies ( See Top 100 in Pet Supplies ) #79 in Aquarium Water Treatments | | Brand Name | Seachem | | Customer Reviews | 4.8 4.8 out of 5 stars (3,009) | | Date First Available | October 2, 2001 | | Department | Unisex-Adult | | Global Trade Identification Number | 00000116046602 | | Included Components | Seachem Flourish Potassium 250ml | | Is Discontinued By Manufacturer | No | | Item Form | Liquid | | Item Type Name | Seachem Flourish Potassium 250ml | | Item Weight | 0.55 Pounds | | Item model number | 466 | | Liquid Volume | 250 Milliliters | | Manufacturer | Seachem Laboratories, Inc. | | Manufacturer | Seachem Laboratories, Inc. | | Manufacturer Part Number | 466 | | Model Number | 466 | | Product Dimensions | 4.9 x 2.4 x 2.2 inches; 8.8 ounces | | Target Species | Fish | | UPC | 015568977138 000116046602 | | Unit Count | 250 Milliliters | | Warranty Description | Warranty | ## Product Details - **Brand:** Seachem - **Item Form:** Liquid - **Item Weight:** 0.55 Pounds - **Liquid Volume:** 250 Milliliters - **Unit Count:** 250 Milliliters ## Images ![Seachem Flourish Potassium 250ml - Image 1](https://m.media-amazon.com/images/I/51mOdi91cQL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Is this safe for bettas?** A: Yes! At the moment, my lonely Betta has been living in a heavily planted 40 gallon tank with some trumpet snails. I have been using only seachem products and they have not not affected him nor the snails, negatively. However use caution when dosing - follow directions. If tank isn’t heavily planted I would half the doses... **Q: Can I use flourish potassium on hibiscus plants?** A: Would work on any plants I would think. **Q: How many ml do i use for a 72 gal and a 75 gal tank?** A: 10 ml per 60 gal. 2 - 3 times a week per the instructions. **Q: Will it work on watermelons** A: This product is intended for aquarium use. I suppose it would work in a garden scenario, but is expensive by comparison to garden fertilizers (which are great for plants, but generally kill fish if you put them in an aquarium). ## Customer Reviews ### ⭐⭐⭐⭐⭐ Great, little goes a long way, effective *by P***O on July 20, 2016* I use a little less than half recommended bottle dosage every day of all seachem ferts (rotate days between trace and flourish complete). Also use online co2 calculator and use just below dose of co2 tank from 5 am to 5pm. Then I air stone at night. Slightly underused recommended fish food once or twice a day. I take no days off. 2/3rd water change and vacuum every 10 days. Perfect numbers and very slow minimal acceptable algae growth on walls to be hardly visibly noticeable. I created my own HOB power filter and pre-filter using a number of materials from amazon sources. I only clean the sponges and not the physical media, squeeze them out in the throw out water that comes out during water change. Aquarium maintenance 101 from a newbie. Use as little substrate as possible to keep plants alive to more easily avoid snails. Clean literally everything before putting into aquarium, better for it to die before going in aquarium than to introduce snails. Scrape the walls of algae at each waterchange. If you get snails, take literally everything out but fish and inverts, and soak it in a low ratio bleach plus water bath for like 20 minutes, this is the only way to kill all pest snails literally. Drain the water to just enough for the fish and inverts to swim and live, then scrub the entire aquarium with a scraper and take out literally anything you can see. Scrape again 3 times. Wipe it all down and make sure all there is you can see is the fish and inverts and clear water. Then wipe again. Add plenty of cycling bacteria from multiple sources you can find on amazon including seachem. Refill the aquarium with the bleach soaked plants decorations subtrate and filter medias. MAKE SURE YOU SOAK IN PLENTY OF DECHLORINATOR AND WATER FOR 20 MINUTES first. None of your plants should die off completely but they will lose and have killed a good amount of their leaves and roots but they should survive and regrow if you fert and change new water and quick cycle with added bacteria I truly hope this helps. My first year with a fully stocked nano tank has been a lot of time reading and experimenting. The pest snail battle was epic but I've been free for 6 months completely. I win. Oh and didn't lose a fish or invert and plants are beyond original growth. This is with having done zero quarantining or adapting at any point. I also cycled from day one, no precycling. Use a 24 hour light with cycling phases and full K spectrum for plants. It is way easier and effective and worth the minor price increase over standard lights. And it is fun Also add Indian leaves and a UV filter Filter floss = crystal clear water. Chemical filtration is entirely unnecessary Have had no issues and made zero adjustments in six months everything has been clear and clean, green growth strong, living things have thrived. Electric heater w built in temperature control at 82 degrees for tropical fish and plants ### ⭐⭐⭐⭐⭐ Very powerful product for all planted aquariums *by J***E on August 6, 2015* Seachem products are very helpful and essential to planted fish tanks for a variety of reasons. If you are just beginning to venture into a live planted aquarium, these are great products to dose. With that being said, you do have to use caution to not over do it. If you are researching this product, let me tell you why and how they work to help you make up your mind: 1. Using the proper doses of seachem products together help your plants grow firm, tall, and gain the beautiful glow they need. 2. Natural algae block!!! A common problem in planted aquariums is algae. Proper dosage of these products provide your plants with nutrients that are designed to be readily absorbed by your plants before algae can get it. Plants and algae compete in the aquarium for nutrients and proper use of seachem products will give your plants a jump start to suck up the nutrients before algae will get to it and grow. 3. Plants are a great natural filter for your aquarium and if you have fish that breed, the rapid growth will allow your fish great coverage and hiding areas to either lay eggs or have their babies. The list goes on and on about why these products do work well, but you have to remember to get everything together for a good planted aquarium to work. Seachem is wonderful enough to provide dosing regimens on their website. I successfully used it as a guide and tweaked it to what my plants needed. ### ⭐⭐⭐⭐⭐ Must have for java fern *by B***E on March 4, 2026* I bought some beautiful Java fern from my local fish store. But within 2 weeks it was not so beautiful. Full of pin holes and brown spots. I kept adding more liquid fertilizer and nothing really changed. After research I realized that a lack of potassium might be the issue so i tried Flourish. All I can say is WOW! It did not help the leaves that were already damaged but the amount of new green growth has been amazing! I put just a drop in my 10gallon tank 2 times per week and could not be happier. ## Frequently Bought Together - Seachem Flourish Potassium 250ml - Seachem Flourish Nitrogen 250ml --- ## 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.co.uk/products/5951852-seachem-flourish-potassium-250ml](https://www.desertcart.co.uk/products/5951852-seachem-flourish-potassium-250ml) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-05-16*