I have a small setup ready to go but I need to know how to get all the good bacteria and nitrites up before planting anything.

My local suppliers do not carry anything for aqua/hydroponics and online shipping is quite pricy. I can get a bag or two of aquarium water from the pet store when I get my fish.

What is my best way to get things started?

  • I've noticed that questions on aquaponics often get little response here at Gardening SE. I know aquaponics is also on topic at Sustainability SE, perhaps you'll get more answers there?
    – THelper
    Dec 2, 2013 at 12:57

3 Answers 3


The bacteria for quick cycling a tank you might be able to find at your local fish store, you will find some aquarists who don't trust that, though, and it'll be expensive for a larger scale pond. You probably are dealing with heartier fish, so you may be willing to risk more.

If you're not in a hurry, though, you can do a fishless cycle using just ammonia. If you set your tank up with sufficient oxygen (bubblers, filters and such) and ammonia (4-5 ppm) and monitor it the bacteria will grow, you'll be able to tell by monitoring your ammonia levels and watching them drop more rapidly. In place of buying pure ammonia you can use fish food, it will break down into the needed components. Don't forget to provide places for the bacteria to grow.

Some people use actual fish to speed up the process as well. If your fish are inexpensive you may try that.

And always the best thing: if you have a friend beg him for some used filter media!

(P.S. Are you setting this up in the winter? Fish have a lowered immune system in cold water- the shock of a new environment in the cold can kill them.)


There are basically 2 steps:

  1. Introduce bacteria

    • You can do so by adding some from a shop, or if you have none available put some sand from a running aquarium in your pond/fish tank. Just get a small jar of it and put it in the tank.
    • Another solution would be to put a sponge in a running aquarium, let it there for few days, then put in your tank.
    • Another solution is to take the sponge from the filter of a running aquarium and "wash" it in your new tank.

    All of the above will give you an initial colony.

  2. Grow the bacteria

    • You will need to feed them. Just drop a bit of fish food in the tank, like if you were feeding a single goldfish. You can also add a spoon of sugar (just a teaspoon, not too much) to boost the process.

    • Then monitor your nitrites, they will stay stable for a while, then suddenly rise, then drop to an acceptable level. You'll be fine by then. But be careful when populating, not to start a second nitrites peak.


The bacteria (and archea) come from the air. No need to buy any but if you do, it will speed up the process. You'll need a source of ammonia to start this off before you add the bacteria otherwise they'll have nothing to work on. Some use fish to provide the ammonia from their respiration, and urine, but you should have a ready source of ammonia yourself by using your own urine. As long as you're healthy, mammalian urine is sterile.

You then need to monitor the ammonia levels and once they are back down to zero, it's safe to add the fish. It may take some weeks using a fishless cycle. The starting ammonia concentration creates the correct numbers of microbes to metabolize it to nitrites and then nitrates. So, you may need to keep adding your ammonia source until you reach the right starting level.

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