






⚡ Ignite your aquarium’s ecosystem with science-backed speed and clarity!
Brightwell Aquatics MicroBacter Start XLF is a 15x concentrated, shrimp-safe nitrifying bacteria solution designed to rapidly establish and maintain biological filtration in freshwater aquariums. It accelerates tank cycling within 5-7 days, reduces harmful ammonia and nitrite levels, and supports high-density fish populations. Ideal for new setups, post-cleaning recovery, and medication aftermath, this American-made formula ensures a stable, vibrant aquatic environment with a shelf life exceeding one year.









| ASIN | B086Z6VTJW |
| Allergen Information | Sulphites Free |
| Brand | Brightwell Aquatics |
| Brand Name | Brightwell Aquatics |
| Customer Reviews | 4.5 out of 5 stars 1,262 Reviews |
| Included Components | MicroBacterStart XLF |
| Item Form | Liquid |
| Item Type Name | Water Conditioner |
| Item Weight | 4.97 Ounces |
| Item form | Liquid |
| Item weight | 4.97 Ounces |
| Liquid Volume | 125 Millilitres |
| Liquid volume | 125 Millilitres |
| Manufacturer | Brightwell Aquatics |
| Manufacturer Part Number | BACSTARTXLF125 |
| Model Number | BACSTARTXLF125 |
| Target Species | Fish |
| UPC | 810086019595 |
| Unit Count | 1 count |
| Unit count | 1 count |
G**️
100 % recommend!!
Amazing product!! My tank was cycling for over a month and no changes, my ammonia 0ppm, nitrite super high and barely any nitrate, and I was using brightwell florin bacter 7 which is great as well but for some reason wasn’t working for this bigger tank. So I did some research and it said I could just substitute the florin Bacter for the micro bacter start XLF since they’re the same brand and are compatible (do your research) so I did and after 4 days dosing it my tank was ready and no nitrites at all!! It was like magic. I recommend this to start cycling the tank since it’s so strong and then continue after water changes with the Florin Bacter7 which is what I’m doing and it’s going great so far. Also keep both in the fridge. One think I must add is that for some reason I thought the bottle was going to be bigger because of the picture they display but it’s still enough because it’s concentrated and it’s only to use once in a while. I also use it when I have ammonia in my nano tank I dose it for 2-3 days and it boosts the nitrifying bacteria 🙌🏻 love it and will buy again and again.
B**E
Great bacteria booster for starting and supporting a cycle
I’ve had very good results using Brightwell Aquatics MicroBacter alongside cycled or seeded bio media. Using both together really helps fast track the cycling process instead of starting from zero. It’s easy to dose and has been especially helpful when setting up new tanks or reinforcing an existing cycle after changes. Pairing it with established media has made cycling much quicker and less stressful. I like keeping it on hand for both new setups and ongoing tank maintenance.
M**S
Cycles tanks quick!
I had been using seachem stability when I started the tank and we were having a few problems like ammonia spikes so I thought I would try this and it got our tank cycled in only two or three days. Its perfect for cycling your tank. I still swear by seachem stability but I learned that stability is more for consistant upkeep of the bacteria rather than Jumpstarting your tank. Overall im very happy with this product!
S**D
It works
Bought it several times already. It helps on estemblishing the fish tanks cycling system effectively.
E**L
errr probably worked?
So I moved from a 29 gallon to a 75 gallon and I only brought one decoration and a sponge filter from the 29 gallon. I noticed after 2 days my ammonia was converting but I honestly can't tell if its because my bacteria survived or because this is a great product. Nonetheless, I'm sure it aided in the process. I kind of bought this cause DrTim's was out but I'm sure it actually does work. Also the cap had a little hole so every time I shook a little would come out. Didn't affect my water clarity or anything. For the price I think it's alright.
Trustpilot
4 days ago
3 weeks ago