--- product_id: 186340323 title: "MicroBacter Start XLM Marine Tank Cycling Aid, 125 ml" brand: "brightwell aquatics" price: "€ 38.29" currency: EUR in_stock: true reviews_count: 9 category: "Brightwell Aquatics" url: https://www.desertcart.hr/products/186340323-microbacter-start-xlm-marine-tank-cycling-aid-125-ml store_origin: HR region: Croatia --- # 15x concentrated power reduces ammonia & nitrite fast cycles tank in 7 days MicroBacter Start XLM Marine Tank Cycling Aid, 125 ml **Brand:** brightwell aquatics **Price:** € 38.29 **Availability:** ✅ In Stock ## Summary > 🌊 Dive into crystal-clear waters faster with MicroBacter Start XLM! ## Quick Answers - **What is this?** MicroBacter Start XLM Marine Tank Cycling Aid, 125 ml by brightwell aquatics - **How much does it cost?** € 38.29 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/186340323-microbacter-start-xlm-marine-tank-cycling-aid-125-ml) ## Best For - brightwell aquatics enthusiasts ## Why This Product - Trusted brightwell aquatics brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Beat New Tank Syndrome:** Achieve a stable, balanced aquarium environment in just 7 days—perfect for new setups or emergency recovery. - • **Proudly American-Made Quality:** Crafted in the USA by Brightwell Aquatics, ensuring premium, shelf-stable performance for over a year. - • **Post-Cleaning & Medication Rescue:** Re-establish beneficial bacteria quickly after tank cleanings or medication treatments to keep fish thriving. - • **Turbocharge Your Tank's Biofilter:** Super concentrated 15x formula accelerates nitrifying bacteria growth for rapid water cycling. - • **Handle High-Density Aquariums with Ease:** Scientifically formulated to reduce toxic ammonia and nitrite even in crowded tanks. ## Overview MicroBacter Start XLM by Brightwell Aquatics is a 15x concentrated liquid bacterial starter designed to rapidly establish and restore biological filtration in saltwater and brackish aquariums. It accelerates tank cycling, typically within 7 days, reduces harmful ammonia and nitrite levels, and supports high-density fish populations. Ideal for new tanks, post-cleaning, or after medication use, this shelf-stable, American-made formula ensures a healthy, balanced aquatic environment. ## Description Brightwell Aquatics MicroBacter Start XLM Experience a new level of aquarium care with Brightwell Aquatics MicroBacter Start XLM – the ultimate solution for achieving a balanced and thriving aquatic environment. Our concentrated formula is designed to establish a new nitrogen cycle or boost an impaired one, ensuring the rapid establishment of biological filtration and creating a stable habitat for your aquatic companions. It’s particularly useful for new startups, resulting in tank cycling in 7 days in most cases. Also useful in emergencies or after medications to re-establish damaged bacteria beds. This advanced blend works effectively to break down nitrogenous waste, keeping your aquarium water pristine. It is meticulously formulated to enhance water quality and eliminate ammonia and nitrite spikes. Whether you're setting up a new tank or maintaining an established one, MicroBacter Start XLM is your go-to solution. Its versatility extends to marine and brackish aquariums, providing powerful support for a diverse range of aquatic environments. FEATURES AT A GLANCE Super concentrated 15x strength formula Useful for rapidly re-establishing nitrification bacteria in case of an emergency Usually cycles in 7 days Ideal in aquaria with high population densities and when adding new fish Best used post-cleaning of rocks and surfaces or after use of medication Prevents “New Tank Syndrome” Supplied in a proprietary base for maximum longevity Formulated utilizing extensive data compiled by microbiologists AMERICAN-MADE EXCELLENCE Trust in the quality and excellence of Brightwell Aquatics, an industry-leading brand committed to providing innovative and scientifically backed aquatic care products. Made in the USA, we consistently strive to deliver advanced superior quality solutions to elevate the vibrancy and health of your aquarium. Review: Very good for water quality - Keeps the tank in good shape Review: Great product for saltwater fish! - Helps cycle your tank, with saltwater fish aquarium. Good for starting up new tanks & anytime you do a water change, it helps keep the bio load good. ## Features - HIGH-POWER TANK WATER STARTER – MicroBacter Start XLM is a powerful 15x concentrated blend designed to kickstart biological filtration in new and existing saltwater aquariums. It enhances water quality, providing a flourishing underwater environment with live, non-pathogenic microbes - RAPID WATER CYCLING – Optimize your aquarium’s health swiftly with this fast-acting supplement. Quickly accelerate the tank's beneficial nitrifying bacteria colonization rates for balance and stability in just 7 days in most cases. It’s the ideal solution when time is crucial - FOR HIGH-DENSITY AQUARIUMS – A scientifically blended formula that assists crowded tanks and effectively reduces ammonia and nitrite levels, all while supporting population density. Supplied in a proprietary base, providing maximum longevity in shipping and in your aquatic ecosystem. Shelf stable for over a year at room temperature - ADVANCED TANK RECOVERY – Perfect for all levels of aquarium enthusiasts and compatible with various sand and rock substrates. Also best used post-cleaning or after use of medications. This solution accelerates the re-establishment rate of fish tank bacteria, after upsets, ensuring your fish thrive - AMERICAN-MADE EXCELLENCE – Brightwell Aquatics is an industry-leading brand committed to providing innovative and scientifically backed aquatic care products. Made in the USA, we consistently deliver advanced superior quality solutions to elevate the vibrancy and health of your aquarium ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B083W4N1T3 | | Allergen Information | Sulphites Free | | Best Sellers Rank | #24,347 in Pet Supplies ( See Top 100 in Pet Supplies ) #209 in Aquarium Water Treatments | | Brand | Brightwell Aquatics | | Brand Name | Brightwell Aquatics | | Customer Reviews | 4.5 out of 5 stars 861 Reviews | | Global Trade Identification Number | 00810086019502 | | Included Components | MicroBacterStart XLM | | Item Form | Liquid | | Item Type Name | Aquarium Bacteria | | Item Weight | 4.97 Ounces | | Liquid Volume | 125 Milliliters | | Manufacturer | Brightwell Aquatics | | Manufacturer Part Number | BACSTARTXLM125 | | Model Number | BACSTARTXLM125 | | Target Species | Fish | | UPC | 810086019502 | | Unit Count | 1 Count | ## Product Details - **Brand:** Brightwell Aquatics - **Item Form:** Liquid - **Item Weight:** 4.97 Ounces - **Liquid Volume:** 125 Milliliters - **Manufacturer:** Brightwell Aquatics ## Images ![MicroBacter Start XLM Marine Tank Cycling Aid, 125 ml - Image 1](https://m.media-amazon.com/images/I/613omAqm-zL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Does this ship with ice packs? How is it insured the bacteria will be alive still after spending all day in a hot 100-110 F delivery truck?** A: It does not ship with ice packs. It is a much more stable product than older competing products. It will typically stand hot delivery trucks for short periods of time and it will typically take a freeze and still be viable, if thawed slowly (never microwave). Can it be killed in transit, yes, but it is not very likely. If you ever have a problem, please contact us and we will make sure you are satisfied. Thanks for the question. **Q: Am i understanding this correctly, you can’t use this product with caribsea dry live rock starting a new tank from scratch?** A: You can use it with dry rock that has been seeded with dry bacteria, but that bacteria is the wrong species to use at this stage of cycling and will prolong the cycle to a month or even longer. MicroBacter Start XLM will still work, but not as efficiently because they will be fighting the other bacteria for nutrients and the different species can even consume each other. You will be better off using real live rock, or Real Reef Rock (TM), rock from another aquarium or a store, bare rock from the land, marco rock or any rock to which dry bacteria has NOT been added. Let XLM work alone and it will do its job wonderously, or use it with normal aquarium bacteria (as in rock kept in an aquarium). If you use dry cysted bacteria, it will cause problems, but in the end you will still cycle (and it will be a good cycle, it will just take a prolonged time to cycle). We just recommend against using other packaged or dry bacterial products at the same time. If you have further questions, or need specific help, please fill out our web form or contact the factory, we will be happy to help. **Q: Is there a way to use this if I have already put live sand in the tank?** A: I use it all the time and my tank has live sand and live rocks. My tank is 3 years old and established. I think it depends upon if your tank is new and on its first cycle or if it is an established tank and you are doing a water change, etc. I believe a first time new tank is where the problem with live sand comes in. Hope this helps. **Q: Can i use this product when adding new fish to an stable reef tank?** A: Yes. I am using this product for last 2 years. Every weekend I put to control on Algee grow problems. But I really don’t understand what’s the relation between adding new fish with this product? When we add new fish we not use KH, CA or MG liquids to maintain Aquarim parameters ? I think you got your answer with logic ## Customer Reviews ### ⭐⭐⭐⭐⭐ Very good for water quality *by L***S on March 18, 2026* Keeps the tank in good shape ### ⭐⭐⭐⭐⭐ Great product for saltwater fish! *by R***R on June 12, 2026* Helps cycle your tank, with saltwater fish aquarium. Good for starting up new tanks & anytime you do a water change, it helps keep the bio load good. ### ⭐⭐⭐⭐⭐ Great *by M***W on April 1, 2026* This will always be my go-to from now on. Works like a charm ## Frequently Bought Together - Brightwell Aquatics MicroBacter Start XLM - Concentrated Freshwater Nitrifying Bacteria - Quick Start Fish Tank Starter, Lift Microbe Levels & Water Filtering - Aquarium Water Treatments, 4.22 fl oz - CaribSea Arag-Alive 20 lb Fiji Pink Sand --- ## 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.hr/products/186340323-microbacter-start-xlm-marine-tank-cycling-aid-125-ml](https://www.desertcart.hr/products/186340323-microbacter-start-xlm-marine-tank-cycling-aid-125-ml) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-06-20*