Explaining Spikes In Cycling

[fulltilt]

If you've read my threads you'll know a few things - I'm new - no, REALLY new!. I bought my first tank ever just before Christmas (second tank shortly after that ) and first put water in ANY tank on Dec 30,2005 but there is some weird things happening.

First, I got a 6' tank that needed some work (lids, foam base, etc), so while I was hunting down supplies I got a 4' tank ready to go. Here's the basic run-down :

- the 4' tank was ready to go pretty much. I tagged it as the "LFS tank" as I will do everything that the LFS tells me to do with this tank. I added Sera Nitrivec for 10 days, and have tested for pH, NO2 and NH3 on (almost) a daily basis since Dec 31. On Jan 7 I added plants and some fish (causing a bit of debate on here), but everything is going well and I haven't lost a fish - yet . Yesterday's readings did show a NO2 spike (of 0.2) after my highest NH3 reading ever on the 10th (of 1.0). So obviously the tank wasn't fully cycled, but with only 6 fish it's probably getting there soon.

- The 6' tank is more of a long term project, so I've taken my time with that and tagged it the "internet tank". This tank will be a full fishless cycle as advised by rdd, and I've tracked down ammonia and done all the right things for this tank. I had to buy gravel, so washed that as well. Sourced a foam base (eventually) and basically took my time getting the thing setup and operational. Working through the first few paragraphs of the fishless cycle I have the filters running, airstone in place, and the water temp stable at 90. I have NOT added ammonia yet. Yesterday, I was going to sit down and calculate the quantity of ammonia to add to get 6ppm, but I took a 'control' reading first and to my surprise :

pH : 7.2 - just like I expected, because the other tank is
NO2 : 0.1 - WHAT??? ... the NO2 reading on my other tank (4') after "bottle cycling" for 10 days and fish in there for 7 always had a 0.0 reading, and yesterday had 0.2
NH3 : 0.25 - the usual reading in my other tank (4') until I added fish.

What is happening here ?
Has the tank started to cycle itself ?
I haven't added anything to it at all - just the water. It's been running for maybe 2 weeks while we "admire the bubbles" from the airstone and dream of what we will do, but has the tank started cycling itself ?

Yesterday, I did add plants to it as well - some pieces snipped off the plants in my other tank, and what is left of a round-leafed plant that the snails have almost demolished.

Another reason why I haven't started cycling the tank, is that my test kit does not test for NO3, so I was going to buy a kit that does that before I started adding ammonia.

Any advice would be great

 

[dgwebster]

its most probable that what you are reading is from the plants. it is also possible that there is a very small source already in the tank as well thats been getting processed, e.g. from being washed.

 

[fulltilt]

But the plants were put in after the readings were taken.

 

[dgwebster]

am going to guess its just been those trace ammounts. im curious, what test kit are you using to get such accurate results?

 

[fulltilt]

Hi,

I'm using a kit called "Fresh Lab" by Red Sea.

Comes with colour cards with the NO2 card readings being : 0,0.05,0.1,0.2,0.5,>1
and the NH3 readings being : 0,0.25,0.5,1.0,2.5,5.0,7.5
there's also pH 6.2-7.4 and 7.4-8.6 on 2 separate cards.

 

[dgwebster]

cheers, will see if i can get some myself from a supplier.

 

[rdd1952]

Since you say the ammonia was at .25 "as you expected", I assume you have ammonia in your tap water. Have you tested your tap water to see if you have ammonia and nitrite present in it? That is always a possibility. It is definitely possible that the tank has started cycling. All it takes is an ammonia source and it can begin. So if you have had water in it for 2 weeks and there was ammonia in that original water (from the tap) then it is definitely trying to cycle.

I use API test kits so I dont' have any experience with the Red Sea kits. The readings on the nitrite kit you have really seem to be a waste. The API kit has .25, .5, 1, 2, 3 & 5. I guess anything over 1 is a problem but you would think they would put a little wider range on the Red Sea ones. Are the colors distinguishable from each other?

 

[fulltilt]

I'm going to test the tap water now - have not done that yet

The Nitrite colours are definitely distinguishable, the ppm/colours are :

0 - green
0.05 - sky blue
0.1 - purple
0.2 - burgundy
0.5 - pink
>1 - dark red

 

[fulltilt]

OMG ... NH3 = 0.25ppm in the tap water !!!

no wonder the NH3 tests were mostly 0.25

Now I need to re-assess where my 6' tank is actually up to in the cycle, but is my maths correct :

400l = 400,000ml

If I want to achieve 6ppm then I really want to add 2.4ml of NH3, to make it :

2.4 : 400000 which is
6 : 1000000

right ?