These Are the Best Nitrifying Bacteria Products for Saltwater Aquariums

These products will help start your tank's cycling process

We independently research, test, review, and recommend the best products—learn more about our process. If you buy something through our links, we may earn a commission.

Fish swimming in a saltwater tank

viridis / Getty Images

There are several products are on the market to help start the cycling process in a tank. Some contain a quantity of the nitrosoma and nitrobacter bacteria, which will help cycle your tank faster (some as fast as one day) than normal. Others contain enzymes that help naturally occurring bacteria grow more rapidly. Some products are added only at set up, while others need to be replenished periodically.

Our Top Picks

Nutrafin Cycle Biological Filter Supplement

Nutrafin Cycle


This is a concentrated bacteria that when added to the aquarium or filter chamber will initiate or strengthen the biological removal of ammonia and nitrate by beneficial bacterial strains. Use 1 teaspoon per 10 gallons weekly.

Microbe-Lift Nite-Out II

 MICROBE-LIFT Nite-Out II Aquarium and Fish Tank Cleaner


Microbe-Lift Nite-Out II by Ecological Labs contains select strains of nitrosomonas, nitrobacter, and nitrospira to eliminate ammonia and nitrite. This specialized bacterial additive rapidly breaks down nitrogen compounds. Anaerobic bacteria are utilized ​in such nitrate-reducing devices such as plenums and Coil Denitrators. Nite-Out II establishes and maintains the necessary bacterial populations required to efficiently process toxic ammonia to nitrite and then to nitrate.

Instant Ocean BIO-Spira

Instant Ocean Bio-Spira
Instant Ocean Bio-Spira. Courtesy of

This product contains patented and patent-pending live nitrifying bacteria that detoxify ammonia and nitrite. BIO-Spira accelerates the establishment of the bacteria necessary for successful biological filtration to prevent fish loss due to new tank syndrome.

In just minutes after adding BIO-Spira to your saltwater aquarium, you can introduce your fish without exposure to dangerous levels of ammonia or nitrite. BIO-Spira can also be used after a water change, when adding new fish, or after medicating your saltwater aquarium. The new shelf-stable formula requires no refrigeration.

Tropical Science Biolabs Nitromax Marine

Nitromax Marine

Tropical Science Biolabs Nitromax Marine is a maximum-density blend containing more than 20 billion nitrosomonas and nitrobacter bacteria to rapidly reduce ammonia and nitrite levels. This two-part solution contains high-density nitrifying bacteria and an oxygenating bacteria booster to dramatically increase efficient biological filtration. Patent-pending formulation keeps live nitrifying bacteria 100 percent viable for an additional nine months after opening when kept refrigerated.

DrTim's Aquatics One and Only Live Nitrifying Bacteria

DrTim's Aquatics One and Only Live Nitrifying Bacteria
DrTim's Aquatics One and Only Live Nitrifying Bacteria.

Unlike many other bacterial additives, fish can be added immediately after use. It eliminates new tank syndrome, instantly creates a biofilter, and naturally removes toxic ammonia and nitrite. Use this when setting up a new aquarium or after water changes and disease. It quickly establishes a natural biological filter. You cannot overdose with this product—use the entire bottle to treat the aquarium. Keep refrigerated for longer life. Two ounces treats up to 30 gallons.

API Quick Start

API Quick Start
API Quick Start.

This convenient water treatment liquid immediately starts the nitrogen cycle in your aquarium, limits toxic ammonia and nitrite in aquarium water, and helps prevent fish loss. Use Quick Start in established aquariums to help maintain an active biological filter.

Quick Start bacterial additive has an extremely long shelf life and requires no refrigeration. It's used for freshwater and saltwater use.

Easy-Life EasyStart Beneficial Bacteria Booster

Easy-Life EasyStart
Easy-Life EasyStart.

Easy-Life EasyStart contains highly active beneficial bacteria cultures that boost the natural nitrifying bacteria to help break down fish waste in your aquarium. EasyStart also removes heavy metals and other chemical pollutants. The accelerated increase in beneficial bacterial also competes with harmful bacteria present in aquarium water.