Fishless Cycling Guide
Water quality is essential to get right if you want healthy attractive fish. In fact, it’s often said that keeping fish is more about keeping water than fish. If your water quality is good then your fish will live longer, be more attractive and your hobby will be much more rewarding.
This article explains how to get your fish tank ready for adding fish. You’ll learn some basics about water chemistry and how fish affect the water they inhabit.
Fish, as part of their biological processes, secrete ammonia from their gills and in urine. In the wild this would be diluted by the environment but in a tank this ammonia builds up quickly to levels that will harm the fish. Ammonia in the water can cause breathing difficulties and burn the fishes skin and gills so obviously this needs to be prevented.
Luckily nature is on your side and provides a way of removing the ammonia. This is known as the Nitrogen Cycle.
The Nitrogen Cycle
The nitrogen cycle might sound like too much science but it’s actually very simple. It’s a three stage process where ‘friendly’ bacteria convert the harmful ammonia to much less harmful nitrate. The diagram below shows how this takes place.
As can be seen there are two types of bacteria that are required for the nitrogen cycle. In simple terms the bacteria consume one compound and emit another.
A New Tank
A newly set up tank will not contain enough of the beneficial bacteria required for the Nitrogen Cycle. Bacteria once given a source of ammonia will start to multiply and colonise the filter and substrate. However these bacteria are slow growing and will need time to multiply to the point of being able to remove enough ammonia for fish to be added to the new tank.
The Solution – Fishless Cycling
As mentioned at the beginning of this article you are going to learn how to prepare your water for fish. This involves getting the nitrogen cycle running by adding a source of ammonia into the tank. There are two methods for this, either adding ammonia from a bottle or dropping small amounts of fish food into the tank as explained below. If you have access to fully cycled media from another tank, squeezing it out in your tank, or adding it to your filter will help start the bacterial colonies you need. Be patient when cycling a tank as it takes 4-6 weeks or even longer to fully cycle a new tank. Remember to treat the water in the tank with water conditioner to remove chlorine or chloramine otherwise bacteria won’t grow.
Fishless Cycling – Ammonia method
For this you’re going to need a bottle of household ammonia from the supermarket or chemist, a syringe, a calculator and a test kit for testing ammonia, nitrite and nitrate. (Test kits are an essential part of fishkeeping. It’s the only way you can be sure what’s going on in your tank.)
Household ammonia is typically 10% ammonia, the quantities used in the calculator are based on this. Commonly added amounts to the tank are between 2ppm and 5ppm (parts per million). We recommend 3ppm as a good level so all following instructions are based around using 3ppm.
1) First you need to know how many litres of water are in your tank. This is easy – measure the height, width and length in centimetres and multiply those figures together and then divide by 1000. For example a tank measuring 100cm by 50cm by 30cm would hold 150 litres. If you have a lot of substrate and rocks in your tank you need to take 10 -15% off your calculated figure to allow for this.
2) Next you need to calculate the amount of ammonia in millilitres (ml) you are going to dose your tank with to bring up the ammonia levels to the desired PPM (parts per million) There are ammonia calculator’s on line or you can just add 1ml at a time using your syringe and test after each dose until you get the desired level.
3) The following day use the ammonia test kit to measure the ammonia in the tank. If it’s below 1ppm (parts per million) redose the tank back up to your desired PPM (parts per million) . It may take several days before you see a significant drop.
4) Repeat step 3 every day. This process is to start the cycle off (the initial bacterial growth) and keep the bacteria alive by feeding them ammonia at the correct concentrations in the tank water.
5) After about a week you can test for nitrite in the water. Ammonia is converted to Nitrite in the first part of the cycle so when you can detect it, it means the cycle has started.
6) Continue testing for ammonia every day. Whenever it drops to 0 redoes the tank back up to the selected level. Also test for nitrite every other day. You should see nitrite rise and then start falling after a few weeks.
7) Start testing for Nitrate after a few weeks. Nitrate is the last part of the process where the bacteria convert the nitrite to nitrate. When the test kit starts showing a fall in the nitrites you should see a rise in the nitrates.
8) Once the Nitrite hits 0, your cycle is almost complete. There is still one very important thing to take care of the nitrate levels will be very high at this point so a water change or two is needed to bring these down. So do a 2x 50% water changes over 2 days or a 100% water change only leaving water in your filters. (but remember your bacteria will need food, so after your water change(s) add fish or continue to dose your tank with ammonia)
The graph below shows how you should expect the levels of ammonia, nitrite and nitrate to rise and fall over time. The graph shows the test results you would see before adding the daily ammonia.
Speeding Up the Cycling Process
There are things you can do to speed along the process of cycling your aquarium.
• Increase the temperature of your aquarium water to 80°F-82°F (27°C-28°C)
• Adding a supplementary product like: ( Seachem Stability, Tetra Safe Start )
Credits by Justin85