MicroBacter CWM

Complete bioculture for temperate marine aquaria


• Formulated specifically for temperate (“cold water”) marine aquaria.

• Dual-phase microbial and enzymatic blend which establishes and maintains biological filtration, enhances the rate of nitrification and denitrification, and reduces amount of latent dissolved- and particulate-organic material in all temperate marine aquaria down to a temperature of 40°F (~4°C).

• Benefits to temperate marine aquaria are: Rapid reduction of organic carbon, ammonia, nitrite, nitrate, and phosphate; Digestion of uneaten/undigested food, excreta, detritus, and other latent organic material, resulting in cleaner and healthier aquarium substrate (without having to physically clean or disturb the substrate bed); Reduction of organic compounds into nutrients that encourage the growth of photosynthetic organisms (e.g. zooxanthellae, macro-/microalgae); Greatly-reduced hydrogen sulfide production; Increase in dissolved oxygen concentration; Decreased availability of existing phosphate to undesirable forms of algae and cyanobacteria; Increased water clarity.

• Supplied in a state of suspended animation for maximum longevity.



250-, 500-ml, 2-, 20-L

Technical Background

The concentration of dissolved and particulate organic materials in any aquatic environment can have a significant impact on the overall appearance of, as well as the health of organisms residing within, that system. Relatively low-nutrient environments are characterized by high water clarity, lack of unpleasant odors, and absence of microalgae and cyanobacteria; this is collectively a result of the lack of nitrogen-, phosphorus-, and carbon-based waste available. Aquaria that are relatively rich in available nutrients have characteristics opposite to the afore mentioned, and are typically not desirable because of the resultant appearance of the system and the difficulty of maintaining healthy aquarium inhabitants.

Brightwell Aquatics MicrōBacterCWM is a selective complex of extremely effective microbes and enzymes that rapidly reduces the concentrations of organic nitrogen, ammonia, nitrite, nitrate, phosphate, and organic carbon in coldwater marine ecosystems, leading to greatly improved water quality. Better water quality typically leads to healthier aquarium inhabitants.  Does not require refrigeration, however storage in a cool, shaded area will prolong the activity, and maximize the shelf-life, of the product.

Instructions and Guidelines

Shake product well before each use. Mix appropriate volume of MicrōBacterCWM (see below) with 250-ml (~8 fl. oz.) of aquarium water in a clean container prior to addition to aquarium. If using a pipette to dispense MicrōBacterCWM below water level of container or aquarium, be sure to thoroughly clean pipette with fresh water prior to placing tube back into MicrōBacterCWM bottle; failure to do so will contaminate the product and cause premature spoiling. Best results may be obtained by adding mixture to external biological filtration system (if applicable). Do not add to pump intake port(s). For best results, use within 1-year of purchase date. Turn protein skimming and UV-sterilization off for a period of 4 hours following addition to aquaria. In nutrient-rich aquaria, a noticeable improvement in water clarity is typically apparent within ~60-minutes of dosing.

Establishing Biological Filtration in new aquaria: Assuming a water temperature of 65°F (~18°C), add 5 ml (1 capful on 250- and 500-ml bottles; 1/2-capful on 2L bottle) per 20 US-gallons (76 L) of aquarium water daily for the first two weeks of use; for each 5°F decrease in water temperature, increase the dosage by 2.5-ml per 20 US-gallons.

General maintenance dosage: Daily dosing will encourage the most stable concentration of available nutrients in any aquarium system. Assuming a water temperature of 65°F (~18°C), begin by dosing with 1-ml per 20 US-gallons per day and monitor concentrations of ammonia, nitrate, and phosphate. For each 5°F drop in water temperature, increase the dosage by 0.5-ml per 20 US-gallons. If nutrient concentrations begin to exceed the desired levels, then increase the dosage by 0.25-ml each day until levels plateau and then decrease to within the desired range; continue to dose this amount for general maintenance of nutrient concentrations. If nitrate concentration increases unchecked and no amount of dosing with MicrōBacterCWM halts the increase, then it is likely that organic carbon has become biolimiting to microbial nutrient uptake. In this event, dose with BioFuelCWM per instructions printed on that product’s label, monitoring nitrate concentration and adjusting the dosage rates of both products as necessary.

Caution: Keep out of reach of children. Not for human consumption.


Purified water, proprietary blend of natural enzymes and non-pathogenic, beneficial microorganisms.





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