Fishless cycling--am I doing something wrong?

[cplawrence]

OK--I have my 75 gallon set up and am trying a fishless cycle using the Ace Hardware ammonia that Tom2K mentioned a while back. I've had the ammonia level between the 2ppm and 4ppm mark on the test kit and have not seen any change in about 2 weeks. I tried tossing in a scoop of gravel from my 29 gallon tank along with one of the plastic plants a few days ago to help get this jump started. I was under the impression that the ammonia to nitrite part happened relatively quickly and that the nitrite to nitrate part took the bulk of the time. Am I just being impatient or should I have seen nitrite by now?
Thanks.

 

[Jchillin]

Since you already had an established tank, you could have also used some of the filter media to help it out.

Time and patience is definitely the rule here. The pure ammonia method is no faster than with fish.

 

[bzbee]

If you're seeding bacteria, have the heat up ~80F and start with NH3 around 4-5ppm, the NH3->NO2 should happen relatively quickly. I would say within 2 weeks, you should be seeing a NO2 spike. I used about 5lb of seed gravel spread throughout my 75G as well as a sponge from one of my filters, pinned against the tank by my heater. Once the NO2 spike occurs, I recommend seeding again. I just deeply gravel vac my other tank and dump the mucky water into the cycling tank. I went from 5ppm NO2 and 10ppm NO3 to 0ppm NO2 and 80ppm pretty much overnight. My 75G tank cycled in 2.5 weeks total.

I disagree with Jchillin about it taking the same time as with fish. If you seed bacteria, you're taking weeks off the cycling time by not having to wait for atmospheric bacteria to make it's way into the tank, and you basically start with the NH3 spike from day one so you save a lot of time waiting for your fish to poop that much.

Just be careful not to overdose the NH3 as I've found the cycle stalls beyond 4-5ppm. (If that happens, just do a PWC to get it back down below 5ppm) And remember to do a big water change before putting in any fish as the NO3 levels will be through the roof!!! Use simple dechlor that doesn't bind NH3 and in fact, avoid anything that could consume the NH3, like plants (unless they're rotting like mine :? ) Also remember to adjust the heat back to whatever your fish need.

PS - I also used the Ace Hardware NH3, but I didn't actually measure the volume. I have airline tubing attached to a syringe and just fill it up to the top of the tubing, and it coincidentally hit ~4ppm (My test kit doesn't measure 5ppm)

 

[Jchillin]

I disagree with Jchillin about it taking the same time as with fish.

I was referring to NH3 only bzbee, not seeding...see what I mentioned about using established media from other tank.

 

[cplawrence]

OK--I'm now seeing nitrites (yahoo!) My question is, should I add ammonia as what I original dosed with is consumed? It seems that if I do, my nitrite level would get high pretty fast, but that if I don't, the bacteria that consume ammonia would begin to die off.
Thanks.

 

[Jchillin]

You dose the same amount of NH3 until your cycle is complete. The NO2 will be spiking at this point. Just make sure the NO2 doesn't go over 5ppm (2ppm is excellent) until you begin to get a steady NO3 reading. When you get 0 NH3, 0 NO2 and @ 10-20 pmm NO3, you are done.

 

[bzbee]

If you don't have a planted tank like JChillin, I would recommend at least halfing the NH3 dose once you start seeing NO2, otherwise you risk stalling the cycle over the long run. I usually do not dose additional NH3 unless I'm planning on a full bio-load immediately after the cycle is completed. If you're only adding <5 fish after the cycle, I would stop dosing the NH3, and monitor it daily until it falls to the lowest measureable levels on the test kit (if there's still measureable NH3, the bacteria has not died off), then top up as necessary to maintain 2-4ppm NH3 until the nitrite spike is gone. This keeps the nitrite spike shorter, and I would recommend seeding again during the nitrite spike to speed things along. Also, NO3 levels will be closer to 80-160ppm if you keep up the full NH3 dose throughout, so be prepared to do a massive PWC, ~70%, before adding fish. These are empirically determined steps that I took in speeding up the fishless cycle on 4 tanks, and with the exception of temporarily stopping NH3 doses and seeding again, are derived from Dr Chris Cow's latest fishless cycle methodology. My longest cycle for all 4 tanks (10/29/37/75) not counting stalls is 17 days for a 75G.