** Become a ThinkFish Super Subscriber **

It takes time and money to keep ThinkFish going, if you'd like to help, then a Subscription of your choice would be fantastic. Your subscription will help fund new articles, help pay for server costs and help fund development and promotion initiatives, helping us bring you more of the good stuff you love! You'll also see less ads. Why not become a Super Subscriber today!?


Author Topic: FISHLESS CYCLING GUIDE  (Read 35906 times)

0 Members and 1 Guest are viewing this topic.

Offline Sue

  • Global Moderator
  • Hero Think Fishy Member
  • *****
  • Posts: 8862
  • Likes: 309
« on: August 15, 2013, 10:19:33 AM »
  • Likes On This Users Post 2
Fish produce ammonia, by breathing it out, and their waste decomposes to make it. Ammonia is toxic to fish – it burns their skin and gills making it difficult for them to breathe. A type of bacteria grows in the filter which turns the ammonia into nitrite (with an ‘i’). Nitrite is also toxic – is stops the fish’s blood absorbing oxygen properly, and causes nerve damage. A second type of bacteria grows in the filter which turns nitrite into nitrate (with an ‘a’). This is only toxic at high levels, and it is removed by regular water changes.
These bacteria take several weeks to grow in enough numbers to cope with the ammonia made by the fish. The process of growing the bacteria is called cycling.

There are two ways to cycle a tank – with fish and without. Both take several weeks to complete. It is difficult to give an exact time as there are so many variables.
Several things can affect how fast the bacteria grow – the pH of the water, the hardness of the water, the temperature of the water etc. The source of the bacteria is your water supply, but your water company adds chlorine or chloramine to kill bacteria. The amount of bacteria that manage to escape being killed will also affect the length of time it takes to complete the cycle.

If fish are put into a tank that has no bacteria in the filter, they will suffer from the effects of ammonia and nitrite poisoning. It requires a lot of hard work on the part of the fishkeeper to keep the fish alive for up to two months while the bacteria grow. This process is called a fish-in cycle.

Alternatively, a fishless cycle can be carried out before fish are put in the tank. This involves adding a source of ammonia to the tank to simulate fish waste, and this encourages the bacteria to grow, so the colonies are already present when fish are added. A fishless cycle can be done by adding fish food or ammonia solution to the tank.
Fish food has the problem that it is harder to control the amount of ammonia that is actually going into the tank as the food has to decompose first, but people who cannot find the correct type of ammonia solution have no choice but to use it. In this case, add fish food every day, removing old food before it starts to grow mouldy, and follow the testing instructions for the ammonia solution method. When the cycle is complete, only add a few fish at first as you won’t know just how many bacteria have grown in the filter. Add more fish a few at a time as for fish-in cycling.

Seeding a filter
With both methods of cycling, a portion of mature media will help to speed the process. A piece of media from an established tank is placed inside the new filter at the beginning of the direction of water flow. If the old media is sponge, it can be cut up to make it fit.
The muck squeezed from a mature filter during cleaning will also help to seed a new filter, but this is less effective than using donated media.

Fishless cycling using ammonia solution

There are several things required for a fishless cycle.

Pure ammonia solution


The ammonia solution must be pure. If there is a list of ingredients, it must have ammonia or ammonium hydroxide, water, and nothing else. If there is perfume, soap, detergent or surfactant listed, don’t buy it. If there are no ingredients listed, and the bottle is see-through, shake it. If the bubbles are large and burst quickly like water, it’s fine. If it foams and the bubbles last a long time, don’t buy it. If in doubt, google the manufacturer’s website.
In the UK, the places that usually sell ammonia are Homebase, in the household cleaning section; eBay; Amazon. Small local diy shops may also sell it. If you find the Jeyes Kleen Off brand, be aware that there are other products in the Kleen Off range; the bottle must have the word ammonia on it.

Testing kit
You will need to be able to test for ammonia, nitrite and pH. A lot of strip testers do not contain ammonia tests. Liquid reagent test kits can be purchased as a master test kit containing everything needed, and they work out cheaper per test. There are several makes on the market. Some testers use ppm as the measure, some use mg/l. These units are so close we can regard them as being the same thing.

If you use a liquid reagent kit, make sure you wash the test tubes thoroughly and dry them with a paper towel/tissue after each use. There have been reports of people getting false readings caused by chemicals left in the tube from last time!

If you have bought the API liquid testers, there are two quirks to be aware of.
Firstly, the ammonia test can show inaccurate results when read under fluorescent tubes and energy saving bulbs. Whenever practical, the ammonia test should be read in daylight and when this is not possible, under an incandescent light bulb or halogen light bulb.
Secondly, the nitrite test can behave oddly if the reading is off the top of the scale. If the liquid in the bottom of the tube turns purple immediately on adding the drops, it is probably too high for the tester to cope with. It may also go an odd shade of greeny blue after mixing and standing. The way to check this is to dilute a sample of tank water with tap water, say 1 fifth tank water and 4 fifths tap water, and measure it again. If the reading is now somewhere on the scale you’ll know your tank water is off the scale.

Measuring dropper
This is for accurately measuring the ammonia solution. A medicine dropper with different amounts marked, or a syringe is ideal. They can be purchased from pharmacies or even eBay. Tip – if buying a syringe from a pharmacy, ask for baby medicine dosing syringes or you’ll get the third degree about why you want one if you just ask for a syringe.

The first thing to do is set up your tank and let it run for a day or so. This gives time to make sure the equipment is working properly, and for any dust from the gravel or sand on the bottom to clear.

While the tank is settling, use your test kit to test your tap water. There may be slight amounts of ammonia and nitrite in the tap water, and probably some nitrate. The UK allows drinking water to contain up to 0.5 ppm ammonia, 0.1ppm nitrite and 50ppm nitrate.
With pH, measure a sample of freshly drawn tap water, and allow a glass of water to stand for 24 hours, then test it again. You will probably find a difference between the two. It is useful to know how much the pH of your water changes on standing - the water in your tank has also stood for a while!
It is also useful, though not vital, to know the KH of your water. A test kit can be bought for this, or the information might be available on your water supplier’s website. If they give it, it will be given in the same section as hardness and may be called alkalinity.


This method differs from the original method. 
That used 5ppm ammonia for cycling; this is now known to be too much as a properly stocked tank produces less than 5ppm ammonia.
It is now known that concentrations of ammonia and nitrite that are too high grow the wrong species of bacteria. This method keeps both of them lower than the older method.
It is now known that the filter bacteria do not die immediately if deprived of food; they become dormant rather than die and can go for several days without food with no problems.

Note: the instructions use measurements in ppm. If your test kit uses mg/l, the numbers are the same.

Set up the tank, fill it with dechlorinated water and let it run for a day to make sure all the equipment is working properly. Set the heater to around 30 deg C as the bacteria multiply faster at higher temperatures than you'll keep your fish at.

1. Calculate your dose of ammonia. This would typically be 0.3ml for every 10 litres of tank water; but because bottles of ammonia vary in concentration, it is better to dose at 0.2ml ammonia per 10 litres, then test after 30 minutes (to allow the ammonia to mix in). If the result is lower than 3.0ppm, add more to get to that reading. Make a note of the total amount of ammonia you add.

2. Do nothing for the next 2 days

3. On the third day after adding ammonia, test for both ammonia and nitrite.

4. Do nothing for the next 2 days.

5. On the sixth day after adding ammonia, test for both ammonia and nitrite.

6. Follow this routine of testing for both ammonia and nitrite every third day until you reach a day where the ammonia reading is less than 0.75 ppm and the nitrite reading is over 2.0ppm. Add the amount of ammonia you used on the first day to get 3ppm.

7. Now start testing every 2 days.

8. When you have two consecutive tests where ammonia is zero (that is, zero at one test and zero again two days later) add one third of the ammonia that you added originally. Yes, you add less ammonia than you did on the first day as this will stop the nitrite level getting too high.

9. Continue testing every 2 days. Whenever the tests show zero ammonia on two consecutive tests but the nitrite is over 1.0ppm, add the one-third dose of ammonia.

10. As soon as you have test results that show ammonia below 0.25ppm and nitrite below 1.0ppm, add the full 3ppm dose amount that you added on the first day.

11. Test 24 hours later

12. If both ammonia and nitrite are zero, the cycle has finished – go to step 14
But if either or both are above zero, continue to test every 24 hours.

13. Repeat steps 10 and 11 until you have zero readings for both ammonia and nitrite 24 hours after adding a full 3ppm dose of ammonia, then go to step 14.

14. The tank is cycled. Do a big water change to remove the nitrate that has been made; at least 75% is needed, even better if water is removed right down to the substrate.
If refilling with a hose rather than buckets, add water to 2 or 3 inches deep, add the amount of dechlorinator for the whole tank, then continue filling. If using buckets, add the dechlorinator to each bucket of new water at the dose for the volume of the bucket.
Turn the heater down to the temperature the fish will need and buy fish.

If you can’t get to the shop as soon as the cycle has finished, add the one-third dose every 2 to 3 days to keep the bacteria fed, then do the big water change just before you go fish shopping.

If you have soft water (that is if you do not have limescale in your kettle or showerhead) it is worth finding out the water's KH. A shop should be able to test this for you. Ask them for the actual number. If it is below 4 degrees/ 70ppm, you are in danger of a pH crash. Ask what to do.

As an example, this is a fishless cycle I did in January to March 2016.

Day 1 - added ammonia (enough to get between the 2 and 4 ppm colours on the tester chart) Stage #1
Day 4 - no change
Day 7 - no change
Day 10 - no change
Day 13 - no change
Day 16 - ammonia still same but just a hint of nitrite though still well below 0.25
Day 19 - same as day 16
Day 21 – same as day 16 [tested a day early as getting frustrated!]
Day 24 - ammonia between 1 and 2, nitrite 0. The ammonia dropped from 2 - 4 to 1 -2 but no idea where it went.
Day 26 - tested after 2 days because getting fed up. Ammonia 1 to 2. Nitrite merest hint.
Day 28 - ammonia 0.5 nitrite > 5 (off the top of the chart). Added ammonia to ~ 3ppm Stage #6
Day 30 - ammonia 0, nitrite >5
Day 32 - ammonia 0, nitrite >5. Zero ammonia on 2 test 2 days apart, added the one third dose of ammonia. Stage #8
Day 34 - ammonia 0, nitrite >5
Day 36 - ammonia 0, nitrite >5. Zero ammonia in 2 tests 2 day apart, added the one third dose of ammonia Stage #8 again
Day 38 - ammonia 0, nitrite >5
Day 40 - ammonia 0, nitrite >5. Zero ammonia on 2 tests 2 days apart, added a one third dose of ammonia. Stage #8 again
Day 42 - ammonia 0, nitrite 0. Added a 2 to 4 ppm dose ammonia Stage #10
Day 43 - ammonia 0.25, nitrite 1.0
Day 44 - ammonia 0, nitrite 0. Added 2 to 4 ppm ammonia. Stage #10
Day 45 - ammonia 0, nitrite 2
Day 46 - ammonia 0, nitrite 0. Added ammonia to 2 to 4 ppm Stage #10 again
Day 47 - ammonia 0, nitrite between 0.5 and 1. Added ammonia to between 2 and 4 ppm Stage #10 yet again
Day 48 - ammonia 0, nitrite 0. Finally stage #14

On day 28 ammonia had finally dropped to below 0.75 and nitrite was over 2.0 so I added the second 3 ppm dose of ammonia and continued testing every two days.

On day 30 I had zero ammonia and nitrite over 1 for the first time.
On day 32 I had zero ammonia and nitrite over 1 for the second time so I added  a 1 ppm dose of ammonia and continued testing every 2 days.

Zero ammonia and nitrite over 1 on days 34 and 36 so added another 1ppm dose of ammonia and continued testing every two days.

Zero ammonia and nitrite over 1 on days 38 and 40 so added another 1 ppm dose of ammonia. Continued testing every 2 days.

Day 42 finally had ammonia below 0.25 and nitrite below 1.0. Added a 3 ppm dose of ammonia and started testing every day.

Day 43 - both above zero. Test again next day.

Day 44 - both zero so added another 3 ppm dose of ammonia.

Note: there was a power cut for 4 hours on Day 44 which might have affected the end of the cycle.

There is a full discussion of this topic here please ask any questions you may have there.

** Become a ThinkFish Super Subscriber **

It takes time and money to keep ThinkFish going, if you'd like to help, then a Subscription of your choice would be fantastic. Your subscription will help fund new articles, help pay for server costs and help fund development and promotion initiatives, helping us bring you more of the good stuff you love! You'll also see less ads. Why not become a Super Subscriber today!?

Assess Tankmates In The Tropical Fish Community Creator

Topics that relate to "FISHLESS CYCLING GUIDE"

  Subject - Started by Replies Last post
1 Replies
Last post April 28, 2013, 03:19:54 PM
by Sue
38 Replies
Last post January 21, 2014, 03:23:17 PM
by Sue
11 Replies
Last post January 24, 2015, 07:19:43 PM
by Sue
11 Replies
Last post January 09, 2015, 05:33:07 PM
by Sanjo
9 Replies
Last post June 01, 2015, 06:58:29 PM
by Sue
10 Replies
Last post January 16, 2017, 09:06:03 PM
by Paddyc
425 Replies
Last post May 19, 2017, 10:08:56 PM
by Matt

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 

Think Fish © 2004-2018 | Keeping Tropical Fish Forum - Everything you need for your Tropical Fish hobby
Tropical Fish Market Place
Legal | Contact Follow Think Fish on: