Cycling An Empty Tank

[TwoTankAmin]

What you have just reported is simply not possible as far as I can see. Here is why.
 
1. You wrote you would add ammonia when your readings for ammonia and nitrite reached 0/0. When you wrote that your reported readings were 0/0.25.
2. You then said you would by adding "6ml ammonia, that should raise it to around 1.3ppm"
3. Using the chemistry involved to do the calculation, The most nitrite that 1 ppm of ammonia can produce is about 2.55 ppm (using API kits).
4. If you were dead accurate at 1.3 ppm of ammonia going in, then the maximum nitrite it can produce is 3.25 ppm. If you were off and had put in more ammonia than you had planned to get 5.0 ppm of nitrite would require just under 2 ppm of ammonia to start.*
5. Ammonia can only lose strength over time, not gain it.
6. If you had a some amount of nitrite oxidizing bacteria before as evidenced by earlier posts, they cannot all have vanished and left the ammonia ones intact.
*(assumes no live plants in the tank)
 
I do not know what is wrong here, but the numbers as reported do not make sense to me.
 
For the number crunchers out there:
 
-Atomic weight of ammonia as NH3 = 17.0305 and as NH4 = 18.0388. (Total ammonia is some of both in most tanks but even at pH 8.8, NH3 will be < 30%. I use 100% NH4 when doing calculations.)
-Atomic weight of nitrite (NO2) = 46.0055.
-Atomic weight of nitrate (NO3) = 62.0049.
 
Atomic weight of Nitrogen (N) = 14.0067, Atomic weight of Hydrogen (H) = 1.00794, Atomic weight of Oxygen (O) = 15.9994
 
FYI when using the nitrogen scale, 1 ppm of NH3 or of NH4 = 1 ppm N02 = 1 ppm NO3 because only the N ions are being counted.

 

[andyG44]

I think it is an artefact of the API test kit. The colours are quite hard to match. When ammonia is 0 there is no hint of green in the test tube. As ammonia increases the tube acquires more of a green tint, but good luck trying to match it precisely. And every "jump" is times two the previous reading : an exponential scale. The same applies to nitrites. 0ppm is easy to see there is no hint of red in the cyan colour, but Looking at 2ppm and 5ppm I can see very, very little difference in the colour. The same between 0.5 and 1.0.
 
Todays readings:
ammonia 0
nitrites 0
 
-----------------------------------
 
I am sure the tank is ready. Assuming I do not add any fish until after the summer holidays, therefore not until September, how often will I need to dose with ammonia to keep things going?

 

[eaglesaquarium]

I'd dose it very 4-5 days.

 

[TwoTankAmin]

It is one thing to add ammonia to cycle a tank, another to hold a cycle for a bit and another to hold a cycle for months. The problem will be algae. If you have no live plants, then you can keep the tank dark which should thwart algae. You will also need to be doing weekly water changes as well to clear nitrate.
 
I would suggest you can add ammonia anywhere from daily to every 3rd day. If daily dose 1-1.5 ppm or 2-3 ppm if you want to go every 3rd day. There are two nice things here. First, the bacteria wont starve if not "fed" every day. Second, even if one were to lose 50% of the bacteria while waiting to add fish, you just have to ramp the ammonia back to a full 3 ppm a few days before you plan to add fish. Any shortfall in bacteria will rapidly vanish as the remaining bacteria can double in a day or two even if they are in slow motion.
 
So what you will do is add 2 or 3 ppm and see how long it takes to hit 0/0. The goal is the same as at the end of the initial cycling, to get 0/0 within 24 hours of adding ammonia.

 

[andyG44]

Ok I think I get it. So far I have added only 6ml of ammonia which brought it to around 1ppm give or take . I will dose with ammonia every 2-3 days until we decide what to do.
 
My wife still wants marine by the way. Can that be turned to marine I wonder.

 

[eaglesaquarium]

I am pretty certain that the bacteria needed for marine are actually different than freshwater.  

 

[TwoTankAmin]

sw and fw are radically different in how they cycle. it is much harder to get a sw tank established than a fw. However, once the tanks are established, it is much less work yo keep things running smoothly in sw than in fw.
 
Eagle is correct. The ammonia bacs in sw are different than those in fw.

 

[andyG44]

tropical it is.
 
It is full of plants. the plants are overgrowing and I have no idea what to do. Today I moved over 4 golden barbs approx 2" each and 2 plecs also 2-2.5". There are also snails in there.
 
That means I will no longer be able add ammonia to keep the tank cycled. Since there are only so few fish in it, tank is literally empty, how will I keep it cycled?

 

[eaglesaquarium]

The fish you added will produce ammonia.  The colony will downsize, but survive.  You can increase the fish group after that... slowly.