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How Can I Speed up Aquarium Cycling?

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A quick guide to speeding up aquarium cycling

Cycling an aquarium is vital

Aquarium Cycling is absolutely essential, if you don’t do it properly you will have nothing but trouble and more than likely, dead fish. Cycling a new aquarium properly can take anywhere between 6 to 8 weeks if you get everything spot on and nothing goes wrong.  So it is quite understandable why people run out of patience.  Running out of patience often results in purchasing fish too early, which results in ‘fish in’ cycling.


Fish in cycling

Fish in cycling is essentially the old fashioned way of aquarium cycling.  This involves having live fish in an uncycled aquarium in order for them to produce the ammonia required to get your cycle going.  As I say, it’s old fashioned, and there is no need for it.  Plus there are several reasons why you shouldn’t do it:

  1. It’s cruel to the fish.  The fish in the aquarium are living in their own waste that is not being dealt with by the filter.  They are essentially being poisoned constantly.  Not very nice for them at all.
  2. It takes longer.  Fish in cycling means you need to keep the ammonia level lower, otherwise, you will have dead fish and have no ammonia being produced.  This means it takes much longer to establish a bacteria colony in your aquarium.
  3. It’s more work.  The fact that ammonia levels need to be kept low means far more regular water changes, daily in most cases to keep them low enough.  Combine that with the extended time it takes and you have a lot more work on your hands for a much longer period of time.


African cichlid pool



How can I speed it up the cycle?

This is a frequently asked question amongst new aquarists who are excited to add some fish to their new aquarium.  It’s totally understandable that you don’t want to wait 8 weeks plus to add fish to your stunning new aquarium.  Many aquarium shops have bottles on sale of ‘ready-made’ bacteria.  This stuff is usually called something like ‘quick start’.  My experience with this stuff personally is fairly limited, I gave it a try once just to see if it worked but I had no success at all.

This seems to be common though and many aquarists who have tried it have ended up with more problems than solutions.  This is because the bacteria in the bottle can’t really be relied upon.  If you have grabbed it straight off the factory line, then maybe it would work, but after it has been sat on a shelf for a while it may not be so useful.  Some bacteria could have starved, it may have been too hot, too cold etc, but there is no way to tell in the average home how much of that bacteria is alive and going to work.

I’ve heard many stories from new aquarists who have used these products and have initially been convinced that their aquarium is cycled, only to have a crash (ammonia spike) not long later.  It would seem that the use of these products can create a false positive.  All in all, quick start type products usually cause more trouble than they are worth. Aquarium Cycling correctly is always the best approach.


So what is the answer to faster aquarium cycling?

The best way to speed up your cycle is to find a friend with a healthy, established aquarium who is willing to give you some of their filter media.  Adding a small amount of filter media from a well-established aquarium can reduce your cycling time to as little as a week or two.  If you do this you will still need to follow normal cycling procedures, adding ammonia to keep it alive, plus to feed the now fast-growing colony.  You will also need to test your water regularly to see how it is getting along.

If you’re really lucky, you may have a friend who has a lot of well-established media on offer, if this is the case then your cycle could be cut to as little as 24 hours.  If you are able to fill your new filter with used media that is full of bacteria, and even better add some used substrate too, your aquarium can be cycled almost immediately.

Once you have added this used media, add some ammonia to feed it.  You can then test the levels in the water as you add it to get a reading of how much is there at the time.  Then check the next day to make sure it has dropped to zero, along with nitrates, leaving you with only nitrates left.

The more used media you can add the better, and the shorter the wait will be.  For a more in-depth guide to aquarium cycling, check out the Seriously Fishy no-nonsense beginners book.  Free on kindle unlimited.


Below is a video from Mr Andy Woods showing this in practice for his new Beani grow out tank, enjoy:



About the author

James @Seriously Fishy

I am a fish keeping enthusiast with over 20 years experience. I currently keep American Cichlids (CA) which are my favourite fish to keep so far. I started Seriously Fishy as I noticed a large volume of people on various web pages looking for help with Aquarium basics. I created the first Seriously Fishy book to solve the issue in 28 pages, that led to the Seriously Fishy UK fish forum and blog.

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