Sadly in this day and age, there are still companies and fish shops out there who say that tanks don't need to be cycled prior to adding fish, or that you can 'Just leave the tank filled with water for two weeks and it will be fine' or 'Just chuck some hardy fish in and then you can add more when they die'.

 

To prepare a tank so that it is no longer an inhospitable environment for your fish means to put it through a nitrogen cycle.

 

What is this I hear you ask?

 

All fish excrete waste, be it from breathing or weeing or pooping and these waste products form ammonia in the water.  This ammonia is poisonous to fish. 

Good bacteria break down this ammonia into nitrite which is also poisonous to fish.

Different good bacteria breaks this down to more harmless nitrate which in normal, healthy, sensibly stocked tank conditions isn't too harmful to fish.

 

In order for the tank to become safe for fish we need to add an ammonia source to the tank before we put any fish in so that the nitrifying bacteria multiplies sufficiently to cope with the ammonia and nitrites produced and thus turn it into less harmful nitrates. 

 

This process in simple terms is known as a cycle.

 

The bacteria will live on all surfaces in the tank and especially in the media contained in the filter systems of our tanks and on the substrate too.  The filter material is the main holder of the bacteria and the filters can be 'matured' or primed ready for

 

Ammonia can be added to the tank in several ways explained below.

 

Cycling with flake food

add 3-4 flakes of food daily, the decaying food will release ammonia and the tank will start the cycling process (add the flake to the tank using some kind of clean net or stocking this way the old flakes can be easily taken out and replaced before they turn bad) it helps keep your substrate nice and clean, its not essential as you can leave the flake in the water but quite a good tip.

Continue adding the flake until ammonia peaks at 5 ppm (parts per million) you are in control of this by the amount flake added. Daily water tests are best to monitor this, a excellent kit is API Freshwater Master Liquid Test Kit it tests for pH, Ammonia, NitrIte and NitrAte. Once you have an Ammonia reading of 5 ppm you should stop adding flake at this point. This will allow the ammonia to fall, don't let your Ammonia fall lower than 1-2 ppm you will need to keep your Ammonia steady at this level, this can be done by adding more flakes as necessary. At this point you will see a rising NitrIte reading continue to test your water daily its quite likely that your NitrIte will then climb off the scale but don't worry it will then start to fall and this will usually happen quickly much quicker than it takes to climb. Your aim is to achieve a Ammonia and NitrIte reading of 0 once this is achieved stop adding flake.


Now the important thing to do is get your NitrAtes back under control this can be done by doing a 70-85% water change thoroughly vacuuming the ceramic media or your chosen substrate, this will bring your Nitrates back in line with your tap water. Let everything run overnight. Then test the water for both ammonia and nitrites if they are still zero and your Nitrates are ideally below 20-25 ppm, the tank is cycled and you're ready to add fish!

Cycling with a pure ammonia source

Do NOT sniff your bottle of ammonia to see what it smells like! It's the main ingredient of smelling salts and will NOT smell nice!***
You'd be amazed how many people I know who have sniffed the bottle when opened and nearly passed out!

Step 1: Add pure source of ammonia up to a reading of 5ppm

Step 2: Measure Nitrite, Ammonia and Nitrate each day, then top up the ammonia readings to 5ppm

Repeat Step 2 until Nitrite readings spike above 5ppm.

Step 3: Measure Nitrite, Ammonia and Nitrate each day, then top up the ammonia readings to between 2-3ppm

Repeat Step 3 until both Nitrite and Ammonia readings are dropping to 0ppm each day.

Step 4: Continue to top up the ammonia reading to between 2-3ppm daily, but now measure Nitrite, Ammonia and Nitrate 12 hours after ammonia added.

Repeat Step 4 until both Nitrite and Ammonia readings are dropping to 0ppm 12 hours after ammonia added.

The cycle is now complete, keep topping up ammonia each day until the day before you are ready to get your fish. On the day you are getting your fish do not add any ammonia, instead do some large water changes to get your Nitrate readings down to acceptable levels i.e. <40ppm.

When adding ammonia for the first time add about half what you think is required to raise the reading to 5ppm, then wait an hour and take a reading. You can then easily work how much the ammonia reading is raised for each ml/drop of ammonia added. You then know what to add to raise the ammonia reading to the initial 5ppm and then the required level each day after.

Make sure you **ONLY** use a pure source of ammonia, the only products I know of that are pure are Jeyes Kleen Off Ammonia (it used to be available from Robert Dyas) and Boots Household Ammonia. If you cannot get hold of one of those types then check the ingredients which should just be Ammonium Hydroxide, probably something like 9%. If there is no list of ingredients shake the bottle and if there is no foam or bubbling then you should be good to go.

Cycling using waterlife Bio-mature and Bacterlife (an increasingly popular method)

usually recommend a temperature range of 70 - 80 for fastest cycling. The temperature should not exceed 80 ideally.


Please find the very latest instruction details for BioMature 120ml.
This gives fuller instructions for use and will be out in the market within the next 2 months.
Please note the doses mentioned below are specific to this size bottle. Always follows dose rates on the bottle supplied as concentrations may vary.

BioMature is a scientifically formulated mixture of those bacterial nutrients, vitamins and mineral salts necessary for the rapid maturation of a bacterial filter in seawater, tropical freshwater, coldwater aquaria and garden ponds.

N.B. Never use BioMature in a system which already contains fish, invertebrates or plants. BioMature is designed for establishing new filters or maintaining empty systems only.

Calculate aquarium capacity:
For litres - [L x W x D] in cms and divide by 1000.
For Imp. Galls. - [L x W x D] in inches and divide by 276.




Directions for use:
Tighten cap and shake bottles.
Use the measuring cup supplied to measure the correct dose.

2.5ml treats 75 litres / 16.5 galls.



Use BioMature once per day.

Test with Waterlife's Ammonia and Nitrite Test Kits.
When a reading of 5 - 10ppm is reached on either test kits, stop the addition of BioMature.

At this point you may add Waterlife's BacterLife daily to speed up the maturation process.

After the ammonia and nitrite readings drop to zero, you are ready to add the first few hardy fishes.
Always stock tanks gradually over the longest possible period of time and do not exceed stocking densities.

Add 2.5ml / 75 litres / 16.5 Imp. Galls. Every 7 days whenever a filtered hospital / quarantine tank is empty of livestock.

The best times to “seed” the tank are at Step 1 and then again when Nitrite readings start showing up.   Seeding a tank can be done in several ways - using matured filter sponges from another set up and running them in your new filter, squishing the brown gunge out of a mature filter into the tank or by placing a matured filter sponge in the tank in a high flow area (wrapped around your new internal filter inlets for eg).

When you do add fish as you have been adding 2-3ppm of ammonia each day you can add quite a lot of stock, I would say 75% of full stocking. In theory 75% of your stock will create less than 2-3ppm of ammonia each day so you will have plenty of bacteria to cope with it.

Do not do any water changes during the fishless cycle or rinse out filter media. After the cycle try to leave your filter media alone for as long as you can i.e. until flow is affected.