cycle aids, vs, better, poor, good

Experiment 1- Cycle Aids: Fritz vs. SeaChem

The purpose of this study is to find which aquarium cycle aid will cycle an aquarium faster and maintain more stable water parameters during the process. The idea of this experiment is establishing a healthy Nitrogen Cycle for an aquarium.

For a complete understanding of the Nitrogen Cycle, please see:

Nitrogen Cycle Basics

In-depth Nitrogen Cycle Info


API Ammonia NH3/NH4+ Test Kit

API Nitrite N02- Test Kit

API High pH Test Kit 7.4-8.8

Fritz Zyme 7 Original- Live Nitrifying Bacteria 16oz

SeaChem Stability 100mL

(3) 10 gal. glass aquarium (38L)

(3) Hydro Sponge Small(5-15gal)

(3) MA 80 Air Pump

(3) ViaAqua 50 watt heaters

(3) 5’ airline tubing

(6) Mollie Fish

(1) Spirulina fish food


Same (2) Mollie fish were placed in (3) same size aquariums (10gal). One 10gal aquarium was a control (no aid). The fish received (.5ml) of food once daily. The same weight and amount of food feed represented the same bio-load per aquarium. All aquariums had to new sponge filters ready to “seed” the aquarium. Fritz Zyme (FZ) and SeaChem Stability (SS) were used as directed (a.1) for a new aquarium “cycle” in the aquariums. Ammonia, Nitrites, and pH were check twice daily for the recommend dose time as per the directions of cycle aids. API test kits were used as directed. Results were recorded twice daily.

A high bio-load test is also preformed, by using (5mls) of fish food daily (5 days). This was to simulate poor aquarium maintenance and an increase in bio-load over a long period of time due to the maintenance. No fish were present in the aquarium. All three variables continued to be monitored.


Ammonia Readings

Nitrite Readings

pH Readings

Ammonia for Fritz SeaChem cycle aid experiement, best cycle aidNitrates for Fritz SeaChem Cycle experiment, best cycle Nitrogen CyclepH Testing


AmmoniaResults– Ammonia was the main variable measured in this experiment. SeaChem Stability was able to keep the lowest reading overall through-out the whole test. Fritz allowed for more ppm of Ammonia, but stabilize over time. The Control was able to be fairly comparable to both cycle-aids.

NitriteResults– Nitrites were the second variable of measure for toxicity of the aquarium water. Both aids were able to manage the Nitrites, while the Control had a much higher spike. During the high-bio test, Fritz did not do as well managing Nitrites.


  • SeaChem was able to keep the lowest parameters for both Ammonia and Nitrites.
  • Both aids were able to complete a healthy cycle.
  • Both aid did best controlling Nitrites, but not for a high bio test.
  • No aid or control allowed for an unmanageable reading. These levels are not best for long-term health, but are also tolerated for short periods.
  • The high bio-load test showed Fritz was not able to keep an established parameter for Nitrites. This could be because the bacteria in both cycle aids for Ammonia and Nitrites are different. The control for Nitrites for Fritz is weaker.
  • Both aids and even the Control can all be used for aiding in the Nitrogen Cycle of an aquarium. Both could also be considered for establishing a cycle. Aid and establishing are not the same.
  • pH was a secondary reading, no reading affected pH and is not really considered in this test.

Additional Discussion:

The Control was able to keep up with both aids fairly well for both aiding in the cycle of the aquarium and establishing the cycle. This is in part, because nature does a good job in managing toxic water.  The results could have also been as good as they were, because a Sponge Filter is a highly efficient filter. This experiment could have also been done using a different form of filtration, such as a Hang on the Back (HOB) or canister filter.

Fritz and SeaChem are two different approaches to live bacteria cycle aids. While both were able to aid in the cycle, but Fritz used much more aid (oz), then SeaChem. Fritz used two whole bottles (160z) for the experiment, while SeaChem used a half of a bottle (50ml total) too do the same Fritz did. The two aids also have their own smell to them, but Fritz is much stronger than SeaChem.



 Fritz Zyme:

Shake well, add directly into aquarium. Add Livestock*

New System 4oz (119ml or 1/2cup) per 10 gal (38L)

(*live stock used for bio-load of the nitrogen cycle)

SeaChem Stability:

Shake Well, Use one capful (5ml) for each 10gal (40L) on first day with a new aquarium. Then use 1 capful for each 20gal (80ml) daily for 7 days. Fish and other aquatics species may be introduced at an time as long as dosage is maintained for 7 days.

Recommend place to purchase:


The TestTest with .5ml food 20150108_103941 FritzSeaChemHigh Bio-Load Test 5ml

.5ml Food.5 ml Spirulina Food


11 thoughts on “Experiment 1- Cycle Aids: Fritz vs. SeaChem”

  1. It’s great that you have done this so that people can actually see what goes on, and understand the process, when a lot of new hobbyists don’t even give cycling a thought.


  2. I am impressed with your experiment. I never have care much for Fritz Zyme. I used it back in the 1970s with varying results. I have heard good reports on Instant Ocean “BIO-Spira Saltwater Aquarium Bacteria”. and I am really interested in Dr. Tim’s “One and Only Nitrifying Bacteria”. I have read in the 1990s some of Dr. Timothy Hovanec’s research on the aquarium nitrogen cycle. Perhaps running experiments on these would be beneficial.


  3. A few comments on making something like this (which is a great start!) more robust scientifically: Do more measures at each time point, then show error (std dev or st error or similar). With a single replicate, the data don’t really have much weight. I would recommend repeating this once per product with 2 control and 2-3 experimental tanks, all receiving the same treatment. Also, a control should be treated exactly the same – same food and fish, but no products. Lastly, dropping food into a tank without fish is not the same as one with. Fish release ammonia directly while decaying food will have to go through a bacterial decomposition to do so. Cheers!


    1. The study was done with the resources BA had. An hour a day for over a Month went into this study. That’s more than any aquarium keeper giving advice based on their one or two uses of something. For what we are talking about here, which is cycle aids, this study was very complete and informative. No stats were need, because each variable kept the nitrogen cycle. Significance was not needed. The graph clearly showed the differences in how the cycle were aided.

      Liked by 1 person

    2. Good work!

      I think you did a nice work in providing a well-documented test.

      I am unclear as to a couple of Wade’s critical comments?
      “Also, a control should be treated exactly the same – same food and fish, but no products”

      From what I read, this is exactly what was performed

      Also: “Lastly, dropping food into a tank without fish is not the same as one with. Fish release ammonia directly while decaying food will have to go through a bacterial decomposition to do so”
      I do not think Wade is very experienced in the hobby or industry to make such a critical statement, as noted by cstrohmeyer, most causes of sudden spikes are exactly that, too much food being added to an aquarium, so again, nice work!

      While you did not provide much analysis of the results, to me this experiment was well documented enough and simple enough to let others draw their own conclusions. This also keeps the potential of an accusation of bias from creeping in, despite the rather odd comments by Shawn.

      I would also concur with cstrohmeyer as per this is exactly what our industry needs.
      Instead of the Amazon, Fish Lore, Reef Central and other sources of anecdotal statements that pass as so-called “good information”, this provides a refreshing alternative.

      In fact here are a couple of my posts about this subject:


  4. I believe there may be a few other studies to consider. There are a lot of variables to Nitrifying Bacteria and how it performs in a aquarium. Including PH, Bio-load, Expiration dates, and Temperature from the manufacturer to its final destination. I really haven’t dissected the article but I thought these might be additional independent studies by large Universities to take into consideration when fully evaluating a product.… \

    Click to access Identification%20of%20nitrifying%20bacteria%20contained%20in%20a%20commercial%20i-1.pdf


    1. Each study linked too, just showed Fritz could control a cycle for the aquarium. The study here at BA also showed Fritz to be able to control a cycle. All variables in the study were able too. Fritz just happened to be the most expensive option, with the less undesirable results.

      Liked by 1 person

  5. Very sorry to hijack the post but I am sure the point of the article is Nitrifying Bacteria education and not promotion of a particular product correct?


    1. The point of the post is exactly what was described in the introduction of the article. It’s was comparing two different products, and seeing how the cycle was aided and established by the two. No product was promoted over another and the results were reported to allow them to speck for themselves.

      Liked by 1 person

  6. As one who partly sponsored and advised on this experiment, I think you did a good job!
    Do not let those who seek to bring you down stop you from further experiments.

    First, clearly no bias was done, other than showing that Fritz-Zyme took a lot more product to achieve results. This is nothing secret from my own use and sale of their products over the years.

    I think for an experiment that is aimed at the average aquarium keeper and meant to be a step well above what often is treated as fact based on Amazon Reviews and s many aquarium forums that use ad-hominem attacks to make their points, this experiment was a great success and gets an A+++
    If you were seeking to find a cure for cancer, then I would say more needs to be done.

    Yes, since I was consulted about the what to do as far as a sudden bio load increase; I suggested using fish food so as to not harm the fish.
    As well based on my 40 years in the professional side of this hobby, the number one reason that caused a surge in bio load is someone dumping copious amounts of fish food in their aquarium. Often the call to my aquarium maintenance company went something like “my kids just poured the entire container of fish food into the aquarium, please help”.
    So I think this criticism was both undeserved and misguided .

    As for Dr. Tims, I personally have used many of his products over the years with mixed results, but admittedly not “One and Only Nitrifying Bacteria”. However I know of others that have with no better results than other methods. More importantly the reason I know longer use his products is in my businesses dealings, in particular with LED lights, I have not found their business dealings to be what I would agree with (I will not go into detail other to say I will never do business with this company)

    Finally, my own experiments in bio filtration in the 1990s showed that the use of seasoned filter media exceeded all methods, but that was not the point of this experiment either

    Liked by 2 people

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