Some chemistry to bear in mind when cycling.

[mattrox]

When fishless cycling the advice is to add about 4ppm of ammonia to start off........

When ammonia is converted to nitrite 3 hydrogen atoms are removed and 2 oxygen atoms are added. NH3 -> NO2

Then when nitrite is converted to nitrate one more oxygen is added.
NO2 -> NO3

Why does this matter, you ask? It matters because ppm is based on mass (weight) Ammonia is 17.04, Nitrite is 46.01 and Nitrate is 62.01.

1 ammonia is converted to form 1 nitrite, 1 nitrite is in turn converted to 1 nitrate. As this is happening the mass is increasing. ppm is eqivalent to milligrams per litre (or liter if you are 'merican). This means the number of milligrams is increasing as the conversion takes place. With out boring you with the calculations, 1 ppm of ammonia forms 2.7 ppm of nitrite then 3.6 ppm of nitrate.

Having said that 4ppm of ammonia -> 10.8ppm nitrite -> 14.4 ppm nitrate

Food for thought when redosing your ammonia because I am not sure at which point too much nitrite stalls a cycle.......

 

[BigJim]

Interesting. I can't say I've seen a case of too much nitrite stalling a cycle. Usually it takes a while before nitrites start forming, then you start seeing nitrates shortly after that.

 

[jrmjrm]

That is true, BigJim, but if you're stuck in a cycle like I am, it seems to make some sense. Using that sort of logic (on a much smaller scale, I'm not very scientific) I thought I should probably reduce my daily ammonia addition because at this point I'm just accumlating nitrites. But, everyone here said to keep adding 4ppm daily, and this is my 5th week in the nitrite phase. I've got nitrates, my ammonia drops from 4ppm to 0ppm within around 15 hours, but nitrites are still up there. I'm guessing it's because they just build and build and build, due to the amount of ammonia I'm adding every day. Once you're in the nitrite phase, I'm really not sure that adding the 4ppm dose of ammonia daily is the way to go... But, I'm no expert.

 

[BigJim]

I'd actually try a PWC if your cycle is stalled. It won't hurt anything, but it might help. My 20L stalled while cycling in a very similar way to yours. It would process 4ppm of ammonia in less than 24 hours and the nitrates would go up, but the nitrites seemed stalled. A PWC got rid of the nitrites and I haven't seen appreciable levels since.

Think of the PWC as the reset button for your aquarium.

 

[Deep Seven]

That is true, BigJim, but if you're stuck in a cycle like I am, it seems to make some sense. Using that sort of logic (on a much smaller scale, I'm not very scientific) I thought I should probably reduce my daily ammonia addition because at this point I'm just accumlating nitrites. But, everyone here said to keep adding 4ppm daily, and this is my 5th week in the nitrite phase. I've got nitrates, my ammonia drops from 4ppm to 0ppm within around 15 hours, but nitrites are still up there. I'm guessing it's because they just build and build and build, due to the amount of ammonia I'm adding every day. Once you're in the nitrite phase, I'm really not sure that adding the 4ppm dose of ammonia daily is the way to go... But, I'm no expert.

+1 I've been thinking a lot about cycling, and I'm thinking of trying something like what you're talking about. Once ammonia starts converting, lowering ammonia doses until nitrites start dropping, then slowly increase ammonia while making sure nitrite keep dropping. If nitrite goes off the scale, PWC to get it back.

 

[mattrox]

What about starting the cycle with 2ppm.... and up it to 4ppm after the cycle is complete to increase the bacterial load. It is quicker to increase a bacterial population than establish it.

I used to fishy cycle because of no access to ammonia in the past, all of it had perfumes or surfactants.....

I have cycled with cardinals, rams, corys on different occasions. The tank was large (70 gal) and the bioload was low. Ammonia and nitrite levels were never allowed to rise above the lowest detectable colour on the test kit. I had the Rams breed during a cycle so I won't enter any argument about stressed fish or cruelty.... but, My point is that the cycle was 6 weeks on the dot each time with low ammonia and nitrite levels with daily (or twice daily) pwcs.

My conclusion is that 2 ppm should be sufficient for a quick cycle and then few days of 4ppm to up the bio capacity of the filter.

I have been thinking about this for some time and have seen many posts about "stalled" cycles with excessive nitrite, but nitrate levels increasing. A confusing situation that seems to generate a lot of questions....

 

[jrmjrm]

I'm with you on this mattrox. Honestly, I think you're on to something here. Just logically that would make more sense. Once the bacteria are there - then you increase the ammonia ppm so that the bacterial population can grow just before you actually add fish. Someone should test this out... Volunteers?

 

[Aquarium1]

Following, this seems very interesting

 

[mattrox]

I have all the seeded media I need and don't anticipate I can test out the theory anytime soon. Maybe I can set aside a tank to trial it on.

 

[jeremyblevins]

well if my gourami gets out of my hospital tank i'll happily test it out

 

[Deep Seven]

I"m starting a 15 gallon tank soon. Just bought the tank today, I get it next weekend. I'm still trying to decide what I'm gonna stock it with, but I'll be definately trying some stuff out for cycling.

So what we want is 2ppm ammonia with daily dosing to replace lost ammonia, then when nitrite spike drops to zero, increase daily ammonia dosing to 4ppm and wait for cycle to finish, keeping a daily journal of the test results.

I may run a control tank if I can, using the exact same conditions, except 4ppm ammonia from the start. And I may also run a few other cycling experiments at the same time, if I can find the appropriate containers to do it in. Again, with daily journal entries for everything.

That sound good? Any suggestions or requests?

 

[mattrox]

That sounds awesome..... Would be really be good to get a streamlined and refined cycling process.

 

[mattrox]

I"m starting a 15 gallon tank soon. Just bought the tank today, I get it next weekend. I'm still trying to decide what I'm gonna stock it with, but I'll be definately trying some stuff out for cycling.

So what we want is 2ppm ammonia with daily dosing to replace lost ammonia, then when nitrite spike drops to zero, increase daily ammonia dosing to 4ppm and wait for cycle to finish, keeping a daily journal of the test results.

I may run a control tank if I can, using the exact same conditions, except 4ppm ammonia from the start. And I may also run a few other cycling experiments at the same time, if I can find the appropriate containers to do it in. Again, with daily journal entries for everything.

That sound good? Any suggestions or requests?

Any updates?

 

[Deep Seven]

I ended up planning a complicated planted tank build which means the cycling process won't be typical.

I do have a quarantee tank I'm thinking of setting up to cycle some media beforehand so when my tanks are ready i have some cycled media to add. When I head out of town this weekend I'll try pick up some ammonia and a test kit.

 

[Marconis]

To the OP, I went as high as like 5.5 nitrite on my first cycle and it stalled the cycle for 27 days. I don't know if that was due to the nitrite or some other factors. Probably the latter.

 

[XimeD]

I am starting my 75gal today and will be doing fishless cycling. I am also a chemist and the 2ppm ammonia dosing followed by increase to 4ppm to "increase the bioload" once the tank cycles makes perfect sense to me.

I will try that and let you guys know how it turns out. However, this is my first time fishless cycling (and my second tank ever) and I don't have another tank to run a control so it won't be the same as what deepseven was planning.

Wish me luck =)

 

[Deep Seven]

Well to be honest, I don't have a control tank right now either. This is my second tank ever, and my first time fishless cycling. I'm no chemist, but I did take chem12 as an elective in high school and really enjoyed it.

I couldn't find any ammonium, (janitor supply store was closed sunday and no hardware stores had any), so my plan to start cycling my QT today fell apart. I hope to have the tank set-up and cycling within a few days.

I'm still kind of planning a real experiment, where I set up a few 1-3 gallon jugs with different parameters and see which parameters contribute to the fastest cycle.

 

[XimeD]

I had a really hard time finding it too, it's actually 10% (by volume) ammonium hydroxide and the only place I could find it in was Ace hardware (its called janitorial strength ammonia cleaning solution). Research suppliers will sell it, but only to schools/universities so that was a no go.

What parameters are you planning on testing? I would try to vary one variable at a time between the jugs.

 

[mattrox]

I'll be following along to see how things go!

 

[Deep Seven]

Yeah, I don't have an Ace Hardware around here, I'll do some calling around tomorrow and find some.

My plan was to set up several jugs all identical, keep one or two unchanged as control, then change one thing on each of the others. I haven't decided exactly what I will do, depends partly on how many jugs I get and how ambitious I feel.

Here are a few ideas I have:
1) Increase temperature
2) Increased or reduced surface agitation (airstone)
3) Different filter media. This could take up a few jugs.
4) Cycling additive, like Tetra Fresh Start.
5) Different dosing regimens, again, this could take a few jugs.
6) High/Low PH and water hardness

Then use the results, excluding cycling additive, to run a cycle using all the parameters that helped cycle faster. Compare all the results and go from there.