more ammonia = faster cycle?

[JohnPaul]

Been thinking about the question in the subject line. Thanks to an antibiotic entirely wiping out my biofilter about two weeks ago (even though the package claimed it was "safe for biofilters," grr), I am in the process of having to re-cycle my tank from scratch. I have some zebra danios and corys in there currently.

Now I realize that any level of ammonia is toxic to fish--but I also realize you need some ammonia in there in order to have the tank cycle at all. However, what impact does the ammonia level have on the bacterial growth? Would there be any benefit, for example, for only doing water changes every 3-4 days and allowing ammonia to hit near 1 ppm? Or should I be changing water every single day and aim to keep ammonia at or below 0.25 ppm? Would I see a faster cycling time in the first case (thinking there is more "food" around so the bacteria should grow faster?) Any input is appreciated.

 

[FancyGuppyGuy]

ghghfghfg

 

[loganj]

My theory, which is unproven and possibly flawed, is that the bacteria will grow at it's maximum rate as long as there is excess food available. I don't think a higher concentration of ammonia will speed things up. I would, in deference to the fish, keep the ammonia levels low and wait for the bacteria to catch up.

 

[jsoong]

Higher concentration (up to a point) will help speed things up <& so will higher temp ... ie 80's compared to 70's). TomK2 here had a thread where he kept the bioload low & ammonia basically undetectable & it took over 40 days for the cycle. I think people using higher levels has faster cycle .... certainly in fishless cycling, with people keeping levels at 2, they had reported cycles in just a few weeks.

I am not sure what the optimal levels are in terms of getting the fastest cycling (high NH3 will also inhibit the bacteria - esp. nitrite converting ones). But, to keep the fishies happy, I would suggest keeping low levels. So what if you have to wait an extrra week or 2?

 

[FancyGuppyGuy]

the first bacteria needs ammonia mainly and a constant source.

the second bacteria needs nitrite and organic wastes. So yes organic wastes are important and there have been studies about the effects of no organic wastes. In one study the type of bacteria would not grow at all without organic wastes.

fishless cycling can take 10 or less days if you do everything right

flucuations in ammonia from 2 to .25 might cause the first bacteria togo dormant again. this is why we see people who change water alot having longer cycle times or problems cycling.

anyhow I have studied these bacteria in depth. They do need nutrients one of the keys is phosphates. they also need plenty of oxygen. the first bacteria prefers PH of around 7.8 the second prefers PH around 7.4.

If you have completely killed them off you might need to have a spike in ammonia up to 3-5 ppm to get them to jump start if you do not have anything to seed your tank with.

I would find something to seed the tank with it will make things alot easier with fish in the tank. if possible up the temp to 78F or so and add extra aireation.

 

[TomK2]

I agree with jsoong:

Starting from scratch, keeping ammonia undetectable with low bioload, my cycle took 40 days. I then heavily seeded a new goldfish tank with gravel and filter material from the established one, went right to 60% bioload, then to 80% bioload in 2 weeks , and it took 2 to 3 weeks with ammonia at 0.25 for a week , maybe one or two days at 0.5ppm. We did water changes about 3 or 4 times a week when the ammonia was detectable. The process might have been effected by an Ich and anchor worm treatment administered by my wife. She also believed the label that said the biofilter would not be harmed by the medications, but we noticed a return of ammonia and nitrite for a few days afterwards, otherwise I think it would have been done around two weeks.

I would think that your biofilter would be more like a seeded tank situation, since I doubt the medications killed all of the bacteria off. I doubt you would notice a huge difference if you let the ammonia levels climb, but your fish might! So what if it takes an extra week or two, make life comfy for the fish and keep the levels as low as you can.

Without fish in the tank, letting the ammonia go up in the 2 to 5 ppm range seems to do the trick, like FancyGuppy Guy states. Do not let your pH plung, a pH below 6.5 is reported to stall the cycle.

 

[JohnPaul]

Thanks for all the replies. My pH tends to stay in the 7.0 - 7.2 range. Twice I've gotten pH readings as high as 7.4, but both of those times it was when ammonia was at 1.0 ppm--not terribly surprising, since ammonia itself is a base, it is going to raise the pH in the tank some when the levels are higher.

I am now 10 days into the "re-cycling" of the tank. 29 gal with with fish listed below. Have been keeping my ammonia around 0.5 ppm by doing water changes about every other day; have had a couple of occasions when ammonia was as high as 1 ppm.

Ten days in, no sign of nitrite or nitrate yet. :x So the wait continues...

 

[TomK2]

One of the things that surprised me with the seeded Goldfish tank was that the nitrite phase was shorter than the ammonia phase, which is contrary to conventional thinking. Since the process was complicated by medication administration, I stopped taking detailed notes (didn't think the notes would be that valid for future reference anymore) but the nitrite phase was shorter. Huh. so maybe you can still get a quick turn around.

 

[malkore]

ammonia levels over 5ppm with start to kill the bacteria off. however, those levels will totally kill fish.

In this situation, you might try to score some Bio-spira to help jump start the tank.

Can I ask what anti-biotic you used that kill the bio-filter? I've used Marycin before without problems.

 

[JohnPaul]

Yes, you may ask. It was Kanamycin, marketed under the name "Kanacyn" by Aquatronics. It comes in a powder that you add directly to the tank water, I capsule per 10 gallons. According to the direction, you treat every other day for 5 days, in other words, you add a dose on day 1, day 3, and day 5.

After my first dose on day 1, by about 6-8 hours later I noticed my water starting to get cloudy. By the next morning, it was very cloudy. By day 3 the water was so cloudy I could only see 3-4" into it, and there was no way I could see completely through the tank front-to-back. The cloudiness was apparently the bacterial die-off. By that point, I suspected what was happening but decided there wasn't much I could do, so I continued treatment. By day 5, I could see 2-3" into the water column, that was it, and had high ammonia and nitrite readings (~ 1 ppm ammonia and 0.5-1 ppm nitrite). First thing next day put the carbon back in my filter, did big water changes (40-50%) each of the next several days. Through the changes, finally got nitrites to 0 and ammonia to the ranges I mentioned earlier in this thread...but I haven't had detectable nitrate readings since the kanamycin treatment.

I did learn two things (the hard way) through this experience: having a hospital tank is not an option, but a necessity...and...never trust what a manufacturer tells you on the label of their product. :x