Fishless cycling question (stalled?) from brand new hobbyist

[bennyblee]

Hi all, this is my first post, I'm trying to get my very first tank started and am worried my fishless cycle is stalled. I was dosing with 10% ammonia and got nitrite and nitrates in the tank, but now ammonia, nitrite, and nitrate levels are all just stuck and not changing.



The tank is 20g with gravel and plastic landscaping/plants. The filter is a hang-on-back with good flow and lots of bubbles at the waterfall. Temperature was started at 80F, which I increased to 84 mid-way through. pH has consistently been in 7.4-7.8 range.


I started using small sprinkles of fish food but become impatient (I know, I know) and then decided to shift to 10% Ace brand household ammonia after five days. There was no ammonia in the tank when I started adding the household ammonia. I also added Fluval Biological Booster for the first 3 days that I was adding ammonia.

I gradually dosed the ammonia up to ~4-5 ppm over the course of several days, and it appeared to fall slightly each day before re-dosing. It fell to about 3 ppm and I was waiting for it to fall more to target 2 ppm, but then it got stuck. For the last 4 days the ammonia doesn't seem to be changing. If I squint hard, MAYBE it has fallen ever so slightly (so hard to tell slight color change using the API master kit), so I added just a touch more ammonia last night (added ~0.5 ppm). I hadn't initially tested for nitrites or nitrates, but once the ammonia got stuck I went ahead and tested both, and found ~2 ppm nitrite and ~5 ppm nitrate, and that's were everything remains. I recently found out a neighbor had a tank so 4 days ago I dropped in a scoop of gravel from his tank but it hasn't made any difference (so far).

So I am now 3 weeks in and I have ammonia, nitrite, and nitrate in the tank but the levels do not appear to be changing. Do I just need to be patient, or do I need to start over? Why would there be nitrite and nitrate initially but then stagnate? Did the bottle bacteria metabolize for a few days but fail to establish, and now I just need to wait for BB populations to seed naturally? Any thoughts would be much appreciated!


Thanks everyone!

 

[Aiken Drum]

I think you are adding too much ammonia. Only redose ammonia if you are seeing it drop below 1ppm and then raise it to 2ppm. Too high levels of ammonia will kill off any beneficial bacteria.

Are you sure your ammonia doesnt have any surfacants, perfumes etc in it? Its just ammonia?

Is there a reason for the fishless cycle? A lot of traffic on this forum is people struggling to cycle a tank or not understanding how to go about cycling. By far, more people have problems with fishless cycles than fish in.

Im going to post a fishless cycle procedure. Have a read through and compare it with what you have been doing. Key though is patience. Expecting it to run to a timetable isnt realistic.

 

[Aiken Drum]

To cycle a tank you need to grow denitrifying bacteria to consume ammonia and nitrite that your tank produces. The bacteria needs an ammonia source to grow colonies sufficient in size to consume all the ammonia and resultant nitrite and turn it into nitrate which typically you remove through your regular water changes.

A fishless cycle uses an ammonia source to replicate the fish waste that a tank of fish would produce. This ammonia source can be pure ammonia, an aquarium specific ammonium chloride product like Dr Tims Ammonium Chloride, a cocktail shrimp or fish food.

Ill assume we are using an ammonium chloride product.

Set up your tank. Make sure everything is running smoothly. Make sure you have used a water conditioner product with any tap water you have put in your tank. If you have an adjustable heater raise the temperature to 28c/82.5f.

You should have a test kit. Preferably a liquid test kit. It should test for ammonia, nitrite, and nitrate.

Dose the ammonia chloride to approx 4ppm and start testing daily for ammonia. Once your ammonia drops below 1ppm redose it back to 2ppm. This may take a couple of weeks.

Start to test daily for ammonia, nitrite and nitrate. Whenever your ammonia drops below 1ppm redose it back to 2ppm.

You should start to see nitrite and possibly nitrate in your daily tests. Over time your nitrite should start to rise and the amount of ammonia should start to drop further. Your ammonia may start to not be detectable in your daily tests. Keep redosing ammonia daily if you see it below 1ppm. Your nitrite may rise off the testing chart. I prefer to keep nitrite within measurable levels so it shouldn’t hurt to do a water change to keep readings on the chart. Remember to add water conditioner whenever you put tap water in the tank. Nitrate should appear in your water test at some point too.

Over time your nitrite should level off and begin to fall in a similar manner to what your ammonia tests did. When you are able to dose ammonia to 2ppm and 24 hours later see 0 ammonia and nitrite you are cycled. At this point you have enough denitrifying bacteria to consume all the ammonia and nitrite of a moderately stocked tank. You may want to continue dosing ammonia for a few days to make sure it continues to consume all the ammonia and nitrite and be sure your cycle has properly established before proceeding.

Your nitrate will likely be very high. Do a big water change to get nitrate down. Preferably below 10ppm. Adjust your temperature to the needs of your fish. Get your fish, acclimate and add to your tank. I would advise stocking lightly to start with and slowly adding fish until fully stocked.

A fishless cycle typically takes 6 to 8 weeks.

A good way to speed up this process would be to put a small amount of filter media from an established filter into your filter, or get a sponge from an established filter and squeeze it into your tank water. Perhaps you have a friend who keeps fish who could let you have some? This will seed your filter with the bacteria you are trying to grow and speed up the process.

Another option is bottled bacteria like Dr Tims One + Only or Tetra Safestart. These products wont instantly cycle a tank as they claim but in a similar manner to adding established filter media they can seed your filter with the bacteria you are trying to grow to establish your cycle. These products are hit and miss as to whether they work at all, but are an option if established filter media isnt obtainable and may speed up the process from several months to several weeks.

 

[bennyblee]

I think you are adding too much ammonia. Only redose ammonia if you are seeing it drop below 1ppm and then raise it to 2ppm. Too high levels of ammonia will kill off any beneficial bacteria.

Are you sure your ammonia doesnt have any surfacants, perfumes etc in it? Its just ammonia?

Is there a reason for the fishless cycle? A lot of traffic on this forum is people struggling to cycle a tank or not understanding how to go about cycling. By far, more people have problems with fishless cycles than fish in.

Im going to post a fishless cycle procedure. Have a read through and compare it with what you have been doing. Key though is patience. Expecting it to run to a timetable isnt realistic.

Thanks, yes from all I've read Ace brand is pure ammonia. I did the "shake test" and no bubbles. I went with the fishless cycle actually because my kids preferred it, the tank was a birthday present for my son, and I said we could try the fish-in cycle but there was going to be a slightly increased risk of the fish not being happy or even not surviving (which I know could still happen after fishless cycling depending on maturity, bioload, etc.) but they said they'd rather wait it out if that might be safer.



So thanks for the post, I've read various instructions for doing this that target anywhere from 2-5 ppm to start and then re-dose to target 1-2 ppm once the nitrites appear. So I thought I was doing everything as directed, but I expected that once the nitrites appeared that the ammonia should continue to fall due to establishment of the ammonia-oxiding bacteria. But here I have nitrites appear with falling ammonia initially but now both the ammonia and nitrites are stuck. Less concerned about the nitrate at this early stage.



Would a water change help? Or just continue to be patient?



Thanks!

 

[Aiken Drum]

1ppm ammonia converts to 2.7ppm nitrite and then 3.6ppm nitrate. So your 2ppm nitrite and 5ppm nitrate tells us very little ammonia has been cycled out. But you have been topping it up, so possibly you have pushed it to a level that killed off the bacteria.

I think your comment about the bottled bacteria not establishing is spot on. I see cycles starting off well, and then stopping. My theory is that the bottled bacteria will consume ammonia from the water column, but if it doesnt establish on filter media it dies off after a short while.

Some people advocate a water change for a stalled cycle. I can see how that could help in circumstances with very low carbonate hardness (your pH wouldnt indicate a KH issue btw). Certainly wont hurt anything to do a small water change, and im always a fan of being proactive and trying things. But it will still take patience and you could easily still be waiting another couple of months.

 

[bennyblee]

Thanks! Will give it a try and continue to be patient...

 

[LHotelUmbraQua]

Benny,

What source or guide or article are you using as your model for fishless cycling?

This is one I have been studying; it seems to be well trusted here. It's easier to advise you when people know what instructions you are following. Look for others at SprucePets.

https://www.aquariumadvice.com/the-almost-complete-guide-and-faq-to-fishless-cycling/

Good luck.

Hi all, this is my first post, I'm trying to get my very first tank started and am worried my fishless cycle is stalled. I was dosing with 10% ammonia and got nitrite and nitrates in the tank, but now ammonia, nitrite, and nitrate levels are all just stuck and not changing.



The tank is 20g with gravel and plastic landscaping/plants. The filter is a hang-on-back with good flow and lots of bubbles at the waterfall. Temperature was started at 80F, which I increased to 84 mid-way through. pH has consistently been in 7.4-7.8 range.


I started using small sprinkles of fish food but become impatient (I know, I know) and then decided to shift to 10% Ace brand household ammonia after five days. There was no ammonia in the tank when I started adding the household ammonia. I also added Fluval Biological Booster for the first 3 days that I was adding ammonia.

I gradually dosed the ammonia up to ~4-5 ppm over the course of several days, and it appeared to fall slightly each day before re-dosing. It fell to about 3 ppm and I was waiting for it to fall more to target 2 ppm, but then it got stuck. For the last 4 days the ammonia doesn't seem to be changing. If I squint hard, MAYBE it has fallen ever so slightly (so hard to tell slight color change using the API master kit), so I added just a touch more ammonia last night (added ~0.5 ppm). I hadn't initially tested for nitrites or nitrates, but once the ammonia got stuck I went ahead and tested both, and found ~2 ppm nitrite and ~5 ppm nitrate, and that's were everything remains. I recently found out a neighbor had a tank so 4 days ago I dropped in a scoop of gravel from his tank but it hasn't made any difference (so far).

So I am now 3 weeks in and I have ammonia, nitrite, and nitrate in the tank but the levels do not appear to be changing. Do I just need to be patient, or do I need to start over? Why would there be nitrite and nitrate initially but then stagnate? Did the bottle bacteria metabolize for a few days but fail to establish, and now I just need to wait for BB populations to seed naturally? Any thoughts would be much appreciated!


Thanks everyone!

 

[bennyblee]

Thanks.


An update: since my last post, ammonia started dropping again, slowly. Taking 2-3 days to fall from 2 ppm to ~0.5 ppm or so, have topped off twice back up to 2 ppm in the last week. Can't tell anymore what the nitrites are, even with dilutions I still can't tell what shade of purple is what with the API master kit... Suffice to say nitrites are not dropping yet, nitrates continuing to rise, however with lots of day-to-day variability.



So just plugging away, patiently...



-Ben

 

[bennyblee]

So not quite sure how to interpret the numbers I am seeing now. First, I was able to find some sponge filter material from an established tank and added it to my HOB filter 2 days ago. That same day, I did a 25% water change to get nitrites to a level easier to measure, and re-dosed ammonia back up to 2 ppm, nitrites (I thought) were down to ~3 ppm, I did not test nitrates. I had stopped checking nitrates a week back as they peaked at 80 and then somehow fell down to 30 over a couple days, I didn't think I was getting accurate results and with the nitrites still not falling I didn't think it mattered.


Yesterday, ammonia fell to 1.5, nitrites were at ~2, nitrates again not tested.



Today, ammonia is unchanged at 1.5, but nitrites have fallen suddenly to 0.25, and nitrates are down to 5 ppm somehow.



My understanding is that nothing metabolizes nitrates, those can only be removed by water exchange. My guess is that my nitrites were actually high and I was interpreting the color incorrectly (because honestly, all the purples look to same to me on the API master kit), and that the previous high nitrate levels were falsely elevated due to the nitrite, and now that those are clearing, the nitrate is now reflecting more accurately. But if that is the case, how can I have falling nitrites after a high peak but only have 5 ppm nitrate? Shouldn't NOW be the time when the nitrates are off the charts?


I double-checked everything and the numbers are all coming out the same. How can I have both falling nitrites AND falling nitrates?

 

[Aiken Drum]

High nitrite can cause a false nitrate reading. If your nitrite falls then you are no longer seeing a false high nitrate reading.

 

[bennyblee]

Thanks Aiken, that is what I suspected, but if I am seeing a ten-fold fall in my nitrites, how come I'm not seeing the nitrates going up? Shouldn't the reason for nitrites falling is that they are being converted to nitrates? Or is there another way for the nitrite to disappear from the tank?

 

[Aiken Drum]

No. You are correct. My bad.

These tests arent that accurate though. Maybe your nitrite and nitrate werent as high as you were reading. Maybe the nitrate is now more than your test says. Maybe nitrite hasnt therefore dropped as much as you think. Maybe the false high nitrate was much higher than the now correct value and that explains the drop despite nitrite now processing out. 1ppm nitrite goes to about 1.5ppm nitrate, so say 10ppm nitrite will result in about 15ppm nitrate which you are seeing as 5ppm nitrate.

I would just discount nitrate. Its the zeros against the ammonia and nitrite thats important.

 

[bennyblee]

Ok thanks, that makes sense to me. I guess the morale of the story is to not obsess over the individual numbers given how inaccurate and subjective the test kit readings are, and just focus on the pattern of falling ammonia and nitrites until you get to 0 in 24 hours.

 

[bennyblee]

FYI, just a follow-up:


Tank completed cycling last weekend after ~ 6 weeks. Challenged with 3.5 ppm ammonia, it will cycle out completely to nitrate in 24 hours. Timing was unfortunate as I needed to wait another week to stock, kept dosing smaller doses until ready.



Just started with my first stocking yesterday, will post a new thread with some additional stocking questions!


-Ben