Adding water during cycle ...

Should be irrellevant, if you are testing and adding ammonia on a regular basis anyhow. Just target 5 ppm and you'll be fine. I'm not sure what the evaporation rate of ammonia is as compared to water.

Keep it there at least until your nitrites start to climb, and then most people reccomend dropping the ammonia dose to about half of what you were doing. It isn't detrimental to keep the amonia level high, so ether way you're fine.
Dave

I agree with daveedka's advice. As soon as you start seeing ammonia drop, you should be adding more to bring to concentration up to your target (e.g., 5 ppm). Personally, I don't drop the ammonia level when nitrites spike, but I don't think it makes a big difference whether or not you do that. Just be sure to keep ammonia at or about 5 ppm and you'll be fine.

HTH,
Jim

2nd day of a fishless cycle

Sorry for jumping in, but I too am in the process of a fishless cycle in a 55 gallon tank.

I read Tom's article and it states to: "add that amount daily until the nitrites spike", then "cut back to 1/2 of the original volume".

Ok, so my 2 questions...

First, the amount to bring it to 4+ was 20ml. after one day the ammonia was down to 2ppm and I brought it back to 4ppm+ by adding 10ml. Should I continue this method or add the 20ml and not test for ammonia, just nitrites?

Second, At what point is a nitrite spike? Is it also 4+ppm?

don't exceed 5ppm

First, this isn't rocket science, there is a lot of room for error. So, dont' stress over things too much.

Second, you want to not go past 5ppm, for high ammonia levels inhibit the action of the next group of bacteria.

So, continue to test for ammonia, and add whatever fraction of that initial dose it takes to get back to near but not above 5ppm. You do want to know when the tank can consume 5ppm of ammonia in a 24 hour period. I'd expect that it might go 20, 10, 13, 15, 20 as the level gets nearer to zero each time.

Start watching for nitrites soon, and as they start to rise cut back on the ammonia. Nitrites will go to something like 2x the ammonia level and that part will take something like twice the time the ammonia period took.

The last day before ammonia goes to zero you will have added 20 ml, or very near that, since the ammonia at that point was near zero and you needed 20 ml the first time. Maybe you are adding 18ml, so when you see the nitrites present and rising, cut back to 10 ml. this will keep the ammonia consuming bacteria going while the nitirite bacteria get started.

BTW, bartman, was your tank somehow innoculated with bacteria? Old equipment, filter squeezings or something? I'm surprised that the second day had such a drop in ammonia.

Thanks anonapersona !

I will try not to sweat too much

Yes I did take some gravel, slime from my other tanks biowheel and a sponge squeeze. (I think I covered all my bases!)

I too was shocked to see that much of a drop, but I was also concerned about adding an additional 20 ml of ammonia if it had not dropped. I was also shocked not to see any measurable nitrites yet ( I guess this is where my impatience kicked in).

No worry though, it sounds like I am on the way to a quick cycle. I'll be patient and let nature do its thing.

BTW for the water chemistry folks out their...

The temp is set at 80F
Ph 8.2
Kh 180
Gh 150-300 (test strips are tough for us color blind folk when they are not dead on)

Thanks again.

One strong cautionary statement on fishless with high dose ammonia throughout the process: You are very likely to force the process into a longer time frame by some inhibition of the nitrite-oxidizers, and at the same time you do need to monitor pH and KH as the process will use up 2x the alkalinity as dropping to the lower amoonia dosage. If you tank's KH/pH are not high to begin with, you may well crash the system if you do not monitor, or at least may drop to unfavorable pH ranges.