Just a note- I no longer make any bones about saying the article here on fishless cycling is one best ignored- especially the 2nd method. Even Dr. Cow who pioneered fishless cycling wrote back in 2001 when he updated it to become the dose and test method suspected that letting ammonia and nitrite levels go way high would mess up the cycle and it could very well be due to the inhibitory effect of those high levels. Research done since the 2001 article support this thoughts but at a much lower ppm level than estimated by Dr. Cow.
Yes, the method expounded on this forum is hopelessly out of date and inadequate. However, high ammonia dosing is useful as the first dose because the idea is to get nitrite into the water column as soon as possible and the higher dose promotes the growth of faster growing (but ultimately the wrong) AOB. Once nitrite shows, the ammonia dose should not exceed 1ppm.
A tank which has absolutely no jump start in any fashion should be cycled in about 45 days +/- 5 days.
I have never had a tank cycle take longer than 3 weeks (with absolutely no added potions or seeded media etc.). Occasionally it's a few days shorter. This is very dependent, however, on the source water's initial nitrifying bacteria level and nutrient content - something we have no control over and which, all other things being equal, I believe accounts for a good part of the differences in cycling times we see. Your cycles, however, are longer because you continuously overdose ammonia, i.e. 5ppm.
Seeding with seasoned media, gravel or potted plants will accelerate this. Given a decent amount of seeding it should reduce the time by about 50%-75%. Given a huge amount of seeding it can be anywhere from instantly cycled to something under 10 days. So when I see posts about folks seeding their tank and then being stuck, especially after cycling for 7 or 8 weeks, I know there is something wrong and it is usually a directly result of dosing too much ammonia as the root cause.
I agree that high ammonia dosing, i.e. the 5ppm that you recommend, is too much. It's far from the only cause of a stalled cycle though. Nutrient deficiency, particularly phosphate, oxygen deficiency, and pH and temperature shock during to water changes or excessive bicarbonate dosing can all cause a stall.
There should not be a point at which a cycle "stalls". Using higher ammonia levels which also engenders higher nitrite levels is counterproductive. One should never have ppm readings over 5 ppm for either ammonia or nitrite (this is much more problematic than ammonia). Because of the inaccuracies involved with testing and test interpretation, I believe that even shooting to cap out at 5 ppm is a poor idea since being under will not hurt anything but being over will.
This is essentially wrong. Many people have cycled, dosing 5ppm ammonia daily, and never changed water, with consequent nitrite levels in the multiple tens of ppm. The inhibitory effect is real but not as bad as the literature would have you believe or the tanks would never cycle (and they do, eventually). The effect is compounded, once the NOB get going, by having to clear tens of ppm of nitrite, further delaying the cycle and this is the main reason why controlling the nitrite level is wise.
High nitrite levels will create acid which causes the pH to drop and as it drops under 7.0 it will begin to inhibit the bacteria.
High nitrite does not create acid. The acidification is from the AOB pumping out hydrogen ions as they convert ammonia to nitrite.
There are ways to adapt the bacteria to acid conditions but this is normally only needed for wild caught fish that have to be kept in such lower pH water. However, there is ample research showing nitrification occurring in acid waters to know it is possible beyond any doubt.
Old news. Not sure what relevance it has here?
However, for most fish keepers a pH dropping under 7.0 will cause increasing issues with cycling the more acid the water gets. On the other side of this coin is the fact that ammonia toxicity is a function of both pH level and temperature level.
Ammonia toxicity drops as the pH and temperatures drop and vice versa.
Not so. Free-ammonia(NH3) toxicity increases as pH reduces. Let me repeat that, pH decrease --> ammonia toxicity increase. However, the amount of free ammonia reduces as pH decreases, so overall ammonia toxicity decreases with decreasing pH.
Finally, there are myriad discussions about finding the right ammonia. Then there are all the problems associated with accurate dosing and testing. For years only folks with access to chemicals had an easy alternative. Today anybody can purchase a bottle of ammonium chloride from anyplace that sells DrTims products. Even if you don't want to use his bottled bacteria, one should use the ammonium chloride. It is pre-formulated so that dosing one drop per gallon of water will result in an ammonia level of 2 ppm. This makes it very easy to control dosing without having to test a lot. Cut the dose in half = 1 ppm, increase it by 50% and its 3 ppm, etc. very easy and reliable. I have been using it for the past 10 months and cycled two tanks fine and held a cycle in another when it went empty of fish for a few weeks. My first 50 tanks cycled fishlessly were done using household ammonia and the drops/gallon method. Not any more
Bottled ammonia is trivially easy to source (at least here in the UK) and ammonium chloride is not. The dosing is also trivially easy once the initial trial dosing has been done so I don't agree with the above paragraph. It just comes over as an advert for your hero DrTim.
Here's the Prime Ordeal 21 day max (fishless) cycling method for completeness:
DO NOT add any additives to the tank (e.g. commercial pH adjusters, sludge busters etc.). All that should go in is pure, dechlorinated water.
Remove or turn off any UV sources (like the ones that sometimes come built into the filter).
Only use a basic dechlorinator during cycling, such as API tap water conditioner, which does not bind to ammonia.
No lights or plants.
Set temperature to 30C
Adjust pH to 8.2 with addition of bicarbonate of soda if pH is less than this. Add crushed coral to the filter to keep it there and/or continue to dose bicarb as necessary.
Add a tiny pinch of flake food to the tank at the start and every seven days thereafter to provide nutrients for the bacteria which may be missing from the source water.
Aerate the tank well. Direct the outflow of your filter, if possible, to create maximum disturbance on the surface of the water. Lower the water level if your filter is not adjustable to achieve the same effect. Add an air stone or two. (Note: This isn't optional, you must do both).
If your filter flow is adjustable set it at maximum. Use the venturi if your filter has one.
Dose 5ppm ammonia as the first dose. Use the calculator to calculate the required dose in mL to achieve 5ppm: http/www.fishforums.net/aquarium-calculator.htm (right at the bottom of the page). Remember to take account of things like substrate, rocks, ornaments etc. which will reduce the advertised tank volume.
Once nitrite shows up, which will probably be on day six or seven, redose ammonia every other day to 1ppm. You don't need to measure the ammonia again, just add one fifth of the initial dose every other day. (Note: In fact no measurement of ammonia is needed at all with this method. Just use the calculator to find what dose you need for your size of tank and ammonia strength and dose that initially, then dose one fifth of that every time thereafter.)
Monitor the nitrite level and change sufficient water to keep it below 5ppm at all times. It is easier to make water changes when the nitrite is at 2ppm or lower, rather than allowing it to rise to 5ppm because less water will have to be changed each time (although, of course, the water changes will then be more frequent). Note: to avoid stalling, ensure the new water is as closely matched in temperature and pH to the tank water as you can.
Approximately two weeks after nitrite first appears your tank should be cycled, i.e. the filter will process 1ppm of ammonia and the resultant nitrite to zero in 12 hours.
After a last, large water change to reduce any nitrate to minimum, the tank can be reasonably stocked immediately but it is wise to allow one more day to ensure that the large water change did not set the filter back.
This method can actually be done with just a nitrite and pH test kit (although I'm not suggesting that you should).
Ammonia sources in the UK (known to be suitable for cycling):
Homebase household ammonia
Jeyes kleen-Off (Google search will bring up lots of vendors).
Toolstation: Barrettine household ammonia.
Robert Dyas
Local small hardware stores - make sure the bottle states the contents as ammonia (or ammonium hydroxide) and water - if it contains surfactants don't risk it.
I have a feeling I may have left something out or oversimplified/underexplained some of it so I'll edit it later as it occurs to me.