You read or hear from “experts,” that nitrifying bacteria mixtures don’t work so don’t waste your money. That statement may have been true 10 years ago but is not today. I will explain why. But first let me acknowledge that I do manufacture and sell a mixture of nitrifying bacteria. However, unlike every other company selling these products, I have been conducting research on nitrifying bacteria for nearly 20 years, did my Ph.D. on nitrifying bacteria in aquaria and have published my work in peer-reviewed, scientific literature. No other company can make those same claims. So I ask you: whose bacteria would you rather buy? A brand developed by a scientist (who is also a life-long fish hobbyist) who is published, and has been studying and developing nitrifying bacteria for aquaria for nearly two decades, or one of the brands that has a big marketing department behind them?

Let me explain why some mixtures work and why you still hear that “they don’t.” 

The right bacteria are different – for years there were only a couple of brands of nitrifying bacteria mixtures on the market. They contained the traditional species mixture of nitrifying bacteria and they did not perform very well. This soured many long time hobbyists and store owners on nitrifying bacteria mixtures, and it is hard to change someone’s opinion. My published research showed that the bacteria responsible for nitrification in aquaria were new species that had never been identified or cultured (subsequent research by other university researchers confirmed and extended my findings). My discoveries led to the development of BioSpira® (trademarks are owned by their respective companies) and later to DrTim’s Aquatics® One & Only Live Nitrifying Bacteria. Many companies now claim their mixtures now contain these bacteria, but they offer no proof and for years, some even denied my research was valid. So one needs to be careful trusting their claims.

Nitrifying bacteria can live in a bottle for a while. Many think that nitrifying bacteria cannot live in a bottle and will say the reason is because nitrifying bacteria don’t form spores like other bacteria. This is a half-truth. Nitrifying bacteria don’t form spores, but that doesn’t mean they can’t last in a bottle (think about it – if nitrifying bacteria could not survive poor conditions, how would they have survived for millions of years?) They can live in a bottle but under optimal conditions, and the time period is about one year. The nitrifying bacteria don’t die in the bottle; their activity level drops and eventually it becomes so low that there is little measurable positive effect when they are poured into the aquarium water. Provided the nitrifying bacteria in the bottle were not subject to bad environmental conditions (see the next paragraph), they can last about one year in a bottle.

No special preservation chemical or substance has been demonstrated to extend this time period. Refrigerating the bacteria is the only thing that has been shown to measurably extend their shelf life.

The solution for the hobbyist is to make sure the bacteria you buy has an easy to understand date label on the bottle. At DrTim’s Aquatics, we label each bottle with an easy to read “best by” date.

Nitrifying bacteria are sensitive to environmental conditions – even when the bacteria in the bottle are the correct species, there are certain environmental conditions that harm and even kill the bacteria while they are in the bottle, leading to their inability to accelerate the establishment of nitrification. The first condition is being exposed to temperatures outside the range they can survive. If the liquid in the bottle freezes, the nitrifying bacteria are killed. It doesn’t matter the brand – freezing kills the nitrifying bacteria. High temperatures may can kill or damage nitrifying bacteria.

Unfortunately, the normal way aquarium products are distributed is awful for nitrifying bacteria. The process is that a pallet of product is shipped by a common carrier to the distributor’s (or chain store’s) warehouse. The product is not shipped in any special containers to protect against heat or cold and the truck is not temperature controlled. Once at the warehouse, the pallet is checked in and stored in the warehouse without any temperature control. The product can be in a warehouse in the middle of Texas or Arizona in the summertime, or Chicago or upstate New York in the wintertime – neither are great conditions for nitrifying bacteria.

When an order is received, the bacteria are packed just like filters or pumps – without any temperature protection. In fact, some distributors pack their trucks on Friday and leave them outside all weekend so they are ready to leave very early Monday morning. Think about the temperature in the trailer of a truck left this way in the Midwest in the wintertime – it does not matter what’s in the bottle, chances are high the nitrifying bacteria are not going to survive.

If you are ordering nitrifying bacteria from the internet, make sure the company you are placing the order with is shipping the bacteria in temperature controlled/protected box during the coldest and hottest times of the year. You might have to pay a little extra, but it will ensure you get a viable product.

At DrTim’s, we pay close attention to the weather and provide the option to ship to our customers at every level (distributors, stores, hobbyists, etc.) in styrofoam boxes with gel packs or heat packs (depending on the time of year).

Some people think that nitrifying bacteria must be kept cold all the time, but this is not true. The easiest way to think about how you should handle nitrifying bacteria is to treat them just like fish in a bag. You wouldn’t leave a bag of fish in your car in direct sunlight, so don’t do that to your bacteria, but they’ll do fine in the car for the ride home without any special container or gel ice (assuming the inside of the car is not freezing or over 110°F!!).

Consumers have some responsibility – they shouldn’t assume the bottle of nitrifying bacteria contains the right mix of species and the bottle has been handled correctly before the consumer bought it (“We’re home free and everything should work, right!”) Well, not exactly. Consumers do have a responsibility/role in making sure the nitrifying bacteria works. They are the last ones in the chain. Over the years I have spoken to many customers and the few that have not had a perfect experience using nitrifying bacteria fall into a few groups:

1) The group that decided not to add the nitrifying bacteria until the ammonia (or nitrite, especially) concentration is off the scale. These people tried to save a little money but in the end they pay a lot more. They stocked the tank heavily and are feeding a lot and now they (and their fish) are in big trouble. The problem is that the correct species of nitrifying bacteria are sensitive to high levels of ammonia or nitrite. I will address this in more detail in another article, but published results show that a major difference between the traditional nitrifying bacteria and the correct one for the aquarium are that the traditional nitrifying bacteria are for sewage treatment situations, which have much much higher concentrations of ammonia and nitrite. The aquarium species of nitrifying bacteria do not tolerate these high levels of ammonia or nitrite. So if you’re experiencing ammonia or nitrite levels of 5 ppm or higher, you need to do a water change before adding the nitrifying bacteria. Adding the nitrifying bacteria at the beginning gives them the best chance for success because they are not inhibited by high concentrations of ammonia or nitrite.

2) The next problem group is those people that overdose with ammonia-removing chemicals. Overdosing the various types of these chemicals inhibits the nitrifying bacteria. Yes, some manufacturers say this is not possible, but the results from talking to many hobbyists with problems getting nitrification to establish, along with my own research, say they are wrong. If your ammonia level is high, the safest thing to do is change some water – don’t just add more (and double or triple dose) with a chemical. And definitely don’t start adding more of another chemical. I have had more than one hobbyist who has bought (or maybe it is more correct to say “been sold”) so many chemicals solutions to add to their new aquarium that it is a wonder anything can live in the “water.” Keep it simple – use one brand of ammonia-chlorine-chloramine remover (yes, I recommend DrTim’s Aquatics AquaCleanse), add the nitrifying bacteria (One & Only, of course) and a few fish (one medium sized fish per two to three gallons) and feed a little two or three times day. Monitor ammonia and nitrite, and you’ll see they stay out of the toxic range, and after a few days you can start to increase the numbers of fish. This is a lot easier than changing water each day, netting dead fish and having a lousy experience setting up your aquarium.

3) The group that plays it safe. They don’t add a nitrifying bacteria mixture, but they think that’s okay because they also don’t add fish or ammonia during the start-up period. They just wait two weeks or so and then figure everything is cycled and ready to go. Of course, they have done nothing but extend the cycling period two weeks. The system needs an ammonia source, whether from fish or ammonium chloride, to feed the bacteria and get nitrification started.

4) The last group is those that decided their fish were sick and dosed the tank with antibiotics, along with nitrifying bacteria, during the cycling period. Just to be clear – nitrifying bacteria are bacteria and antibiotics will kill them too. I have had more than one customer call us to say they’re having problems getting their tank cycled only to learn, after much prodding to tell us everything they did, to say, “Well, come to think of it, my fish looked sick so I also added this antibiotic.”

Nitrifying bacteria mixtures do work. But like everything else, there are reputable brands (based on real science) and there are cheap, worthless brands. Also, just like fish and corals, nitrifying bacteria are living organisms and can be killed or drastically harmed by poor conditions or mistreatment. 

Applied correctly and treated well, nitrifying bacteria mixtures in a bottle work and can dramatically reduce new tank syndrome and get your tank up and running with no hassles.

Good fishkeeping.


Arnold Kreger

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