Brightwell Aquatics MicroBacter Start XLF – Concentrated Freshwater Nitrifying Bacteria – Quick Start Fish Tank Starter, Lift Microbe Levels & Water Filtering – Aquarium Water Treatments, 4.22 fl oz
$11.50





Price: $11.50
(as of Oct 16, 2025 11:38:49 UTC – Details)
Brightwell Aquatics MicroBacter Start XLF Experience a new level of aquarium care with Brightwell Aquatics MicroBacter Start XLF – the ultimate solution for achieving a balanced and thriving aquatic environment. Our concentrated formula is designed to boost the nitrogen cycle in your aquarium, 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 5 to 7 days in most cases. This shrimp safe advanced blend works effectively to break down organic 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 XLF is your go-to solution. Its versatility extends to fish and invertebrate freshwater aquariums and is particularly effective for live planted 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 5-7 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.
Package Dimensions : 4.6 x 3.5 x 1.5 inches; 4.8 ounces
Item model number : BACSTARTXLF125
Date First Available : April 10, 2020
Manufacturer : Brightwell Aquatics
ASIN : B086Z6VTJW
Best Sellers Rank: #10,957 in Pet Supplies (See Top 100 in Pet Supplies) #81 in Aquarium Water Treatments
Customer Reviews: 4.5 4.5 out of 5 stars 1,251 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
HIGH-POWER TANK STARTER – MicroBacter Start XLF is a powerful 15x concentrated blend designed to kickstart biological filtration in new tanks and existing freshwater 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 shrimp safe fast-acting solution. Quickly accelerate the tank’s beneficial nitrifying bacteria population for balance and stability in just 5-7 days. It’s the ideal solution when time is crucial
FOR HIGH-DENSITY AQUARIUMS – A scientifically blended formula that caters to 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. It has a shelf life of over a year at room temperature.
ADVANCED TANK RECOVERY – Perfect for all levels of aquarium enthusiasts and compatible with various sand and rock substrates. Best used post-cleaning or after use of medications. This ammonia remover accelerates the re-establishment rate of fish tank bacteria, 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
Customers say
Customers find the bacteria treatment effective at boosting beneficial bacteria and quickly cycling tanks. The product receives positive feedback for its quality as a starter for aquariums, though opinions on water clarity are mixed, with some reporting very cloudy water. While some customers say it’s worth the money, others find it pricey, and ammonia levels show mixed results – some report zero ammonia while others say it doesn’t lower levels.
8 reviews for Brightwell Aquatics MicroBacter Start XLF – Concentrated Freshwater Nitrifying Bacteria – Quick Start Fish Tank Starter, Lift Microbe Levels & Water Filtering – Aquarium Water Treatments, 4.22 fl oz
Add a review
$11.50
Keith Simon –
Good stuff worth the money
Absolute best way to start your tropical fish tank and have a perfect environment for fish survival. This stuff is a must and it works well.
Daniella Cunningham –
Love it!!
This worked great! Wonderful purchase for cycling my axolotl tank, and worked like a charm. Would recommend ðð¼
Nate3030 –
Works fast and effectively
Worked good to start out fish tank out
RDM –
Consistent quality bacteria boost
This product has always given a boost to my aquarium’s beneficial bacteria after a water change or when changing the media in my canister filter. Its a little pricey, but quality products usually are.
Dara Leary –
Highly recommend
Works well and a good price.
Cheyenne –
I like it
New to fish keeping I like this
Cyndie Stevens –
This stuff works
I was having a bit of a problem ‘cycling’ the 125-gallon tank with Seachem Stability. Ordered the Brightwell Aquatics MicroBacterStart XLF and, combined with Fluval’s Biological Enhancer added on top of the Seachem Stability, the tank was completely cycled within 48 hours. Granted, the Seachem had the ammonia taken care of, but the nitrites were just not budging and would escalate rapidly without major water changes and additions of Seachem Prime daily. I am SOOO glad to have found the Brightwell product.
Lisa M –
Great stuff!
I am on my second bottle of this. I used it to assist in the cycle of a heavily planted 20 gallon tank. Never had an ammonia issue. All shrimp, snails and fish added have done well. I have started using it in all my tanks after water changes.