Changing from fishless cycle to fish in

[Mon]

Hi there, has anyone convert a fishless cycle to fish in? I did a fishless with Dr tims ammonia. On day 19 and i didnt top up ammonia for 2 days,  im not sure if i stalled the cycle.  Amm hit 0, Nitrite is steady at 2 ppm & nitrate 10ppm. I added bit of ammonia after that.

What should i do? Keep topping up ammonia,  do a waterchange?

If i stalled my cycle, very tempted to do a waterchange & do a fish in instead. What are your thoughts?

[Pepere]

The bacteria that metabolize ammonia to nitrite establishes itself quicker in my experience.  The nitrite to nitrate bacteria seemed to take a whole lot longer.

 

patience  works…

 

I would just be waiting right now…

[face]

Not putting ammonia in for a few days won’t really do anything  bad to your cycle it takes a long time to kill bacteria like that 

as for if you want to do fish in do a 100% water change and treat it like any normal fish in cycle keeping ammonia and nitrites low maybe add some salt to help with the nitrite but it’s basically the same nothing changes 

[Mon]

Patience is definitely required on my part. I think i will wait longer. Do i need to keep topping up ammonia at this stage? So confused as i get conflicting advice. 

[jwcarlson]

You can, as stated above, do 100% water change and put fish in.  

Not sure what to suggest regarding adding ammonia.  I'm not a fishless cycle person.  Nitrite to nitrate does take longer than ammonia to nitrite as stated above.  Quite significantly longer.  And, I believe, you can get nitrite high enough to retard the growth of the bacteria that consumes it.

[Galabar]

It could take up to 40 days for your nitrite level to go down to zero.  Adding fish at this point (or ammonia) won't speed it up.  The only way to speed it up (other than adding seasoned filter media) would have been to add the nitrite at the beginning.  However, it's difficult to get nitrite and, unlike Dr. Tim's Ammonia, there isn't really a good, "packaged" version of nitrite to add to your tank.

You should see your nitrite levels start to decrease in about a week.

Edited April 11 by Galabar

[AtomicSunfish]

I’m doing fishless cycle, too. However, instead of bottled cultures and ammonia, I seeded with media from established aquaria, put in bladder snails, and feed them. This provides the nitrogenous waste the beneficial bacteria need, without risking fish (even hardy ones). This works because you still have animals and waste in the tank, just not vertebrates.

[Pepere]

On 4/10/2024 at 9:32 PM, Mon said:

Patience is definitely required on my part. I think i will wait longer. Do i need to keep topping up ammonia at this stage? So confused as i get conflicting advice. 

If continuing with fishless, I would monitor nitrites and water change as needed to keep it under 2 ppm.  
 

I would add another dose of ammonia when nitrites fall to under 0.5 ppm without a water change doing it.

raising tank temp, adding extra aeration and adding some carbonates if kh is low can help the bacteria colony grow.

[doktor zhivago]

The nitrite bacteria just take forever. Chemosynthesis of ammonia and nitrite produces orders of magnitude less energy than photosynthesis or carbon based heterotrophy, so nitrifying bacteria and archae just grow really really slow (think weeks to months). There's really no quick way to cycle without using filter media from another tank. 

[Mon]

Appreciate all your help. I'm so happy to see blue (nitrite) today. Am i cycled now?

If i am, my plan is to dose to 2 ppm ammonia & fingers crossed in 24 hrs , i'll have zero ammonia & nitrite. Do a 80% water change? 

[AllFishNoBrakes]

Looks like it! Your plan of dosing ammonia again, and then ensuring it’s able to convert all the way to nitrite in 24 hours sounds excellent. Assume that happens, to a big water change like you mentioned, and you’re off to the races!

[Whitecloud09]

Yep, looks like your done. One more dose of ammonia, after that if it goes to 0 within 24 hours, I would do a water change and do a 30-50% water change, any size of a water change is fine, and then I wait a couple of days then go and get fish, and remember, make sure you check ammonia still after adding fish for a couple of days, then test every week @Mon.

[Mon]

Sadly, ammonia & nitrite didn"t go down after 24 hours. Ammonia at 1ppm & nitrite at 0.25. 

As suggested above, i'm gonna do a 100% waterchange today & slowly add fish.

What happens if i keep detecting ammonia in my tests? Do i keep doing water changes? 

Thank you

[madmark285]

On 4/13/2024 at 4:52 PM, Mon said:

As suggested above, i'm gonna do a 100% waterchange today & slowly add fish.

As someone else wisely pointed out, overfeeding the fish is the major source of ammonia for new tanks. 

[AllFishNoBrakes]

On 4/13/2024 at 2:52 PM, Mon said:

What happens if i keep detecting ammonia in my tests? Do i keep doing water changes?

If you don’t have fish, you can do nothing. If you do have fish, then yes you want to water change. 

[Galabar]

On 4/13/2024 at 1:52 PM, Mon said:

Sadly, ammonia & nitrite didn"t go down after 24 hours. Ammonia at 1ppm & nitrite at 0.25. 

As suggested above, i'm gonna do a 100% waterchange today & slowly add fish.

What happens if i keep detecting ammonia in my tests? Do i keep doing water changes? 

Thank you

It looks like you are close.  Just wait a couple of days to see if that ammonia goes to 0 (along with the nitrite).  At this point, you can either wait or do a large water change and add fish. If you add fish, feed sparingly.

[Mon]

I did a large waterchange & off i went to get some fish. My kids have waited long enough. I have neon tetras, corys and rose tetras.

Thanks everyone ☺️

[Galabar]

Just a warning: I've never been able to keep neon tetras alive.  I'm not sure, but I don't think it's my fault... 😉

On the flip side of that, my black neon tetras, ember tetras, and diamond tetras seem like they'll die of old age... 🙂

 

 

Edited April 15 by Galabar

[NikkiRae]

Patience is key. In my experience, it has never taken longer than a week after this point. You could do a fish in cycle at this point if you want to sacrifice them. At those levels, you would stress the heck out of any fish, or kill them. Or you will end up chasing your tail with water changes if you don't like watching fish suffer. 

[Pepere]

Cycling a tank without introducing cycled media generally took me about 6-8 weeks to get it to the point where it could metabolize a 2 ppm challenge dose of ammonia to 0 ammonia, o nitrites in 24 hours.

 

It takes time for the bacteria colony to grow and mature. It would metabolize a 2 ppm challenge to 0 ammonia, 0 nitrite reliably, but not in 24 hours.

 

Putting fish in now isnt going to speed up the process of that bacteria colony establishing itself and maturing.  It is still going to take several weeks.  It will make checking ammonia and nitrite levels and doing frequent water changes much more important.

Bear in mind also that if you decide to treat the tank with quarantine meds, where the biofilter is so young, the beneficial bacteria could very well get wiled out by the meds.  I have had that happen to me.

[MattyM]

I like bottled bacteria - Fritz and API Quickstart seem to work best for me. It still takes a week or two, but I found as long as the nitrites are low, like under 1, and I don't overstock, the fish can easily handle it (articles have shown nitrite levels this low are not harmful), especially in a well planted tank. And the bacteria need some nitrite to feed on and grow. If the nitrites creep up past 1, a small water change and/or prime dosing, and sometimes dose more bacteria as needed. Eventually I test and get the blue color for nitrites. I still do this even if I used some established media - the bottled bacteria is just handy to have around when starting up a new tank.