Trying a “no cycle” start up on this next tank…

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Magnum Man

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Jun 21, 2023
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Southern MN
In the next week or so my next 45 gallon gets wet… I have a few fish here, in holding tanks, because they became available, before this tank is up and running…. It doesn’t seem like anyone should worry about cycling a tank, that has other aquariums… I either run multiple Aquaclear 70’s or Tidal 75’s on all my bigger tanks, and will be adding 2 new Tidal’s to this tank… I kind of only clean my filters, when the flow is noticeably reduced… I have a couple in need of cleaning… I would think squeezing out my filter sponges on any of these filters into a dish pan full of old tank water, to preclean them, is better than bacteria in a bottle for the new filter sponges… repeatedly squeezing the new filter sponges in this bio saturated water before installing them into the new filters, as well as splitting out some of the ceramic media into each new filter, is going to precycle this tank, from the filters… not to worry about losing too much ceramic media, I don’t personally think they give you enough of that in either filter, so I keep a big bag of ceramic donuts here… they are terrible to have with your coffee, but have more surface area, than the media that comes with either filter… so I add extra when I clean them…. Pre soaking the bags of ceramic media in the pan of bio soup, before installing them in the new filters seems logical as well…

So, with my RO water, and pre-seeded filters, and a light bio load, I’ll be trying a “no cycle” start up on this next tank
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I would get the filters running on an established tank, oh, sometime around yesterday. Let the filters get solidly seeded, and transfer them over after about 3 weeks. That's how I cycle new tanks. Stock lightly to allow the bacteria to grow and spread, and you can have a normally cycled tank in a few weeks.
That is what I’m trying in my new 20 gallon long. But I also added Tetra Safe Start Plus since I was certain placing an old filter into my new tank would be enough.
Hello Magnum. Well, here we go again with one of my favorite subjects and that's tanks. Whether it be cycling, natural, water changes or whatever. So, cycling isn't a problem. Set up the tank and fill it with treated tap water and some brand of bacteria starter. I've used API, but there are others. Allow the tank to run for a couple of days to establish the water temperature. You can add eight to 10 small fish in 45 gallons. I used a dozen Buenos Aires Tetras in my 50 gallon. Change out half the tank water every three to four days and always use the water treatment and bacteria starter. You can feed just a bit every couple of days. After a couple of months, you can add a few more fish and back off the water change to half weekly. No slacking though! Now, I know you've already got a plan in place. So, if you want, you can ignore this post. There is more than one way to prepare a tank for fish.

I would get the filters running on an established tank, oh, sometime around yesterday. Let the filters get solidly seeded, and transfer them over after about 3 weeks. That's how I cycle new tanks. Stock lightly to allow the bacteria to grow and spread, and you can have a normally cycled tank in a few weeks.
This is what I did when I asked Gary's advice on cycling my very low KH tank a while back, and it worked like a charm! I had the pre-seeded sponge filter (3 weeks in an established tank), about a metric ton of frogbit, and only six neon tetra. No ammonia spikes at all. Actually, I think I need to get some nitrogen supplement for the frogbit. They're a little too good at handling bioload and they've been going yellow for a while now.

I definitely think transferring over whole media/whole filters is important. When you squeeze out a sponge or other filter media, I honestly doubt you're getting much BB in that water. The bacteria grow on surfaces, and from experience, we know that they don't wash off of those surfaces easily, which is why we can squeeze out a sponge to clean it and it still works fine as biological media. The people who recommend just doing a squeeze or two of water into a new tank from an old, dirty sponge to "instantly" cycle have the right train of thought, but I think they're ultimately just giving the tank a couple initial doses of fish waste...

I've used this method along with seeded filters from my other tanks and it has worked every single time for me. Prime/stability once a day and daily testing, water change after a week and continue to do prime/stability for up to 14 days. Pretty confident since I have used this to start my L046 pleco tank with thousands of dollars in fish amongst my other tanks. Never had an issue

My testing results have never shown ammonia spikes or any nitrite at all with decently stocked (14 L046 in this case) tanks. I change water once a week about 50-75% and nothing else
I have no idea of how many tanks I've started. I did 40 2 years ago after my move, 20 more before I went away last summer, and hundreds over the years. I crashed one in 1988. I should have known better. But none since, and none before. I've been using the 'run the filter on an established tank' method since the very early 1990s, way back in the last century.

I only dechlorinate, and here, have very clean water - no nitrates from these taps. But I keep a lot of delicate and difficult species.
If you move bacteria from a cycled tank to a new and youi also add Stability, The stability does nothing, it is all being done by what you transferred from tthe cycled path. Well actually thr Stability may become food for other microorganisms. So it may help in that respect, but nothing in stability is doing any of the cycling.

It is easy to think it is but none of us can see or measure what is going on. Only a well equiped lab can do this.

I do not pay any attention to anybody who offers to help with a fish -in cycle. They are doing nothing good for the hobby, for the fish and especially not for folks just entering the hobby.

That vid Ceez posted should never be shown to any new fish keeper. And adding Prime and Stability for 14 days actually slowed your cycle it did nothing to speed it up. Had you added a bottle of actual nitrifying bacteria you would have needed to do this only once amnd with some ammonia in the water the tanks would be ready to stock in a couple of days. If you added the proper amount of bacteria you could have fully stocked the tank.

The secret to having a great filtration set-up is massive` media of the proper sort. Why do folks thing undergravel filters work so well? 3 inches of the proper sized substrate is an awfully massive amount of bio-media. And unlike 3 inches of substrate without a UGF which will only host nitrifying bacteria to a depth of well under an inch, the UGF is oxygenated the endtire depth and therefore the endtire substrate can host the aerobic nitrifiers.

Just because one pours a bottle of useless spores into a tank and then that tank is cycle some time later does not mean that those spores had anything to do with establishing the cycle in the tank. SeaChem knows Stability doesn't cycle a tank. But the are not willing to say so prominently. But they know-->

Bear in mind that until the mid 1990s the prevailing thinging was that the bacteria in tanks were the same as the ones in wastewater. But nobody had set out to confirm this until Dr. Timothy Hovanec decide to take on this task as his Pd.D. thesis. He did the science add he could not find any of the bacteria that were supposed to be there.

When he reported to jis advisor that he could not find the bacteria, his advodor told Dr. H, "You are new to doing all of this testing. Yopu must have made a mistake, Do it again." So Dr. H did it again and got the same results. And if you want to read the paper which was ultimately published in a peer reviewed journal,

Hovanec, T.A. and DeLong, E.F., 1996. Comparative analysis of nitrifying bacteria associated with freshwater and marine aquaria. Applied and environmental microbiology, 62(8), pp.2888-2896.

Three nucleic acid probes, two for autotrophic ammonia-oxidizing bacteria of the b subdivision of the class Proteobacteria and one for a subdivision nitrite-oxidizing bacteria, were developed and used to study nitrifying bacterial phylotypes associated with various freshwater and seawater aquarium biofilters. Nitrosomonas europaea and related species were detected in all nitrifying seawater systems and accounted for as much as 20% of the total eubacterial rRNA. In contrast, nitrifying bacteria belonging to the b-proteobacterial subdivision were detected in only two samples from freshwater aquaria showing vigorous nitrification rates. rRNA originating from nitrite-oxidizing a subdivision proteobacteria was not detected in samples from either aquarium environment. The data obtained indicate that chemolithotrophic ammonia oxidation in the freshwater aquaria was not due to b-proteobacterial phylotypes related to members of the genus Nitrosomonas and their close relatives, the organisms usually implicated in freshwater nitrification. It is likely that nitrification in natural environments is even more complex than nitrification in these simple systems and is less well characterized with regard to the microorganisms responsible.
Since the above paper the ammonia and nitrite bacteria inFw and SW ghave been better identified. Then it was discovered that there are Ammonia Oxidizing Archaea and finally that the Nitrospira identified by Dr. H. et al as the ones oxidixing nitrite to nitrate are also able to convert ammonia to nitrate on thei own. This was considered to ne finding holy grail of nitrifing bacteria.

Seachem has no published scientici papers which support the idea that what is in Stability has anything to do with nitrifying bacteria. And when Hovanec at al did their nitrospira paper they ran a series of tanks using Cycle. What happened in the tanks with Cycle was that the bacteria that went into the tank fromthe bottle were not found weeks later when the tanks were deemed fully cycled.

Hovanec, T.A., Taylor, L.T., Blakis, A. and Delong, E.F., 1998. Nitrospira-like bacteria associated with nitrite oxidation in freshwater aquaria. Applied and environmental microbiology, 64(1), pp.258-264


Oxidation of nitrite to nitrate in aquaria is typically attributed to bacteria belonging to the genus Nitrobacter which are members of the α subdivision of the class Proteobacteria. In order to identify bacteria responsible for nitrite oxidation in aquaria, clone libraries of rRNA genes were developed from biofilms of several freshwater aquaria. Analysis of the rDNA libraries, along with results from denaturing gradient gel electrophoresis (DGGE) on frequently sampled biofilms, indicated the presence of putative nitrite-oxidizing bacteria closely related to other members of the genus Nitrospira. Nucleic acid hybridization experiments with rRNA from biofilms of freshwater aquaria demonstrated thatNitrospira-like rRNA comprised nearly 5% of the rRNA extracted from the biofilms during the establishment of nitrification. Nitrite-oxidizing bacteria belonging to the α subdivision of the class Proteobacteria (e.g., Nitrobacter spp.) were not detected in these samples. Aquaria which received a commercial preparation containing Nitrobacter species did not show evidence of Nitrobacter growth and development but did develop substantial populations of Nitrospira-like species. Time series analysis of rDNA phylotypes on aquaria biofilms by DGGE, combined with nitrite and nitrate analysis, showed a correspondence between the appearance of Nitrospira-like bacterial ribosomal DNA and the initiation of nitrite oxidation. In total, the data suggest that Nitrobacter winogradskyi and close relatives were not the dominant nitrite-oxidizing bacteria in freshwater aquaria. Instead, nitrite oxidation in freshwater aquaria appeared to be mediated by bacteria closely related to Nitrospira moscoviensis and Nitrospira marina.

Here area few snippets from the rest of the paper:

Three of the aquaria (the treatment group) were each given doses of 8 ml of bacterial additive (Cycle; Rolf C. Hagen Inc., Mansfield, Mass.) on the first day and once every 7 days afterwards for an additional 3 weeks. The other three aquaria were the control group and did not receive an additive.

Results regarding the beneficial effects of the addition of a bacterial additive containing Nitrobacter species were equivocal. While nitrite levels in treated aquaria decreased earlier than those in nontreated aquaria, there was no evidence that Nitrobacterspecies were actively growing in these aquaria. It is possible that the levels of Nitrobacter species were below the limits of detection of our techniques. However, since Nitrospira-like bacteria were readily detected and that their establishment coincided with nitrite oxidation we postulate that Nitrospira-like organisms, and not Nitrobacter species, are the major nitrite oxidizers in the freshwater aquarium environment. It is possible that the addition of bacterial mixtures supplies vitamins and other nutrients which generally stimulate the growth of the nitrifying assemblages, fostering their growth and development and indirectly stimulating nitrite oxidation.

You can read the entire paper here

There is a very simple fact here. The science supporting Dr. H's work and subsequent confirmation by others scientists is there for anybody to read. What you cannot find in the science are any peer reviewed research papers which provide support for the other cycling products on the market. There is no paper showing Stability, Cycle, Quick Start etc. work to establish the nitrogen cycle in aquariums.

There is a reason for this lack of scientific evidence.

Here are three of my lists of papers bookmarked on this subject. In order for them to be in the list means I have actually read the paper.

And these are my links relating to the Archaea or Archaea v.s. Bacteria.

probably in theory, you could do a 50% water change every other day for a few weeks, & never pay for an additive, as long as the tank was never overstocked according to size...

of course doing so, would rely on the introduction of nitrifying bacteria, from somewhere... so... where does nitrifying bacteria naturally come from, in a new aquarium??? the air???, from driftwood, or other natural aquarium "scape" like plants, from the fish themselves, from their gills, or slime coat, or poop??? spontaneous combustion???
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Holey, moley and Oh, my goodness! This thread has got to be the record for some of the longest posts, I've ever seen. Some of these posters are better people than I am. At my age, I'd either fall asleep or die of starvation before finishing all the typing and cutting and pasting. Way to go, I admire your diligence!!!


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