Fish Less Cycle Too Fast?

[pob_16]

Hi everyone,

This is my first post on here, but I have been an avid reader for quite some time now. I am not new to the hobby, but after a number of years have decided to upgrade my tank. Now it is the first time I have tried to do a fish less cycle and just wanted to make sure I am going about it correctly as I have had some speedy results.

Some background to what I have done so far.

Set up the tank, which is a Juwel Rio 300, on the 10th of January. The substrate is a layer of TetraPlant complete covered with play sand from B&Q. Water parameters from the tap = NH4 0ppm, NO2 0ppm, NO3 20ppm and pH 8.0. KH 150ppm/8.4deg. Tank temp was at 76degF.


Left the equipment running for a day to make sure everything was fine and then added the Ammonia on the 11th January to 4ppm. (Using API test kit and no 5ppm on the test card.) The same day I added about 11 plants and also set up my pressurised CO2.

On the 12th, readings were the same but I added a mature filter sponge from my old tank and also some bog wood from the old tank. I also increased the tank temp to 78degF.

Readings did not alter until the 15th.

NH4 = 2ppm
NO2 = off the chart
NO3 = down to 10ppm (can only think the plants have removed some Nitrate)

I raised the levels of Ammonia back to 4ppm and by the 17th (today) they were dropping to zero, but NO2 was still off the chart.

So my question I suppose, dose everything seem to be going OK? After reading numerous posts I thought I would be in for the long haul and not see anything for a number of weeks never mind 4 days!

Thanks for and comments.

 

[rdd1952]

Hello and welcome to the forum.

Since you used a sponge from the other tank, it would stand to reason that the results would come quickly since you had a good build-up of bacteria to start with. The reason tthat the nitrite is still off the chart is because of the fact that 1 ppm of ammonia will yield 2.7 ppm of nitrite. So the original 4 ppm of ammonia would put he nitrite over 10.

It isn't normal for the nitrate to drop (seriously doubt the plants had anything other than a minor effect). Nitrate tests can be dodgy though so it could have just been an erronous test (probably the original one with 20ppm basically from the tap although some people do have high nitrate in their tap water).

You may want to do a partial water change to get the nitrite back on the chart so you can see what is happening and to help it cycle faster. On the other hand, if you test nitrate and it is rising, then you know nitrite is processing.

 

[Truck]

plants can absorb ammonia too!

 

[rdd1952]

They can indeed use ammonia in it's pure form rather than it being processed. I'm sure some of it is in this case but since the nitrite is rising, ammonia is definitely being processed to nitrite.

 

[pob_16]

Thanks for the adivice. Hopefully the rest of the cycle will be as quick!

 

[waterdrop]

Hi Pob and welcome to TFF!

A really clear first post with really complete information about the start of your fishless cycle: congrats!

To address your question I'd say yes, you're doing quite well, probably because of an excellent "seeding" of ammonia oxidizing bacteria (A-Bacs) from your mature sponge, the plants and the bogwood. As RDD says, those A-Bacs will be pumping out probably too much nitrite(NO2) at the moment for the number of nitrogen oxidizing bacteria (N-Bacs) that you currently appear to have.

The major question in your case is to what extent we'll be able to ascribe ammonia, nitrite and nitrate level changes to nitrification (changes made by the bacteria) and to what extent it might be ascribed to the plants (absorption by plant body and roots, which occurs especially for ammonia and nitrate.) The process of following along and undstanding the sequence of events in a fishless cycling can different in a heavily planted tank with CO2. In fact, a planted tank cycle is sometimes called a "silent cycle" (probably because the readings of ammonia seem not present, or "silent", but not sure about the origin of this "silent cycle" label.)

As an aside, I believe its a definate thing that plants preferentially absorb ammonia over nitrate(NO3) as a source of nitrogen uptake, but I've not found threads recently on TFF that help to quantify this difference. It could easily be that it varies significantly by plant species, which would make generalizations very difficult. RDD may be pretty up on this and perhaps its true these plants could only have accounted for a minor amount of the nitrate(NO3) drop from 20ppm to 10ppm. I think it would possibly make for interesting discussion among the planted folks. (?)

As RDD says, conducting the nitrate(NO3) tests is notoriously error-prone and its reasonable that you should look at the back of the color chart card or other instructions and make sure you are following all the shaking instructions completely.

Regardless though, your job as a fishless cycler is not to let any questions about plants or nitrates go beyond just something to "think about." You should just keep topping up ammonia to 4ppm (or a shade above as you get the feel for guessing what 5ppm might be) (well, in point of fact you can actually just dose 2 or 3ppm during the "nitrite spike" phase you are in and then gradually ease it back up to 5ppm near the end when its dropping to zero in close to 12 hours instead of taking 24 hours.)

The big test is to be getting both ammonia and nitrite(NO2) to drop to zero in 12 hours after ammonia was added.

~~waterdrop~~

 

[rdd1952]

you are following all the shaking instructions completely.

This is the key as reagent 2 is prone to lumping up. If it has been a while since you've used the kit, that bottle may require more than the 30 seconds of shaking that the insturctions say.

 

[pob_16]

Hi, thanks again for the info and help.

As regards to the reagent 2, it is a relatively newish kit that I have been using on my other tank and I give it a good shake for the 30 seconds stated on the back of the card. Will have to wait until tomorrow and see the results. It may have just been a one off.

Back to the cycle, would you recommend doing a large water change to help reduce the NO2?

Cheers,

Pob_16

 

[pob_16]

Todays results:

NH3 0.25
NO2 off chart
NO3 5ppm ?

Tested the NO3 twice and came out the same. Think I will be a new test kit.

 

[waterdrop]

There's every reason to think your fishless cycle is doing fine. Your tap pH is 8 and even though your nitrites are high I wouldn't necessarily do a water change at this point. And nitrates are not enough of a reason to go out and get another test kit at the this point I don't think.

~~waterdrop~~