Cycle stalled? Ammonia up, nitrites 0, nitrates high

[dragon14]

Long story short, our (fishless) cycle in the 5g tank was coming along nicely. We accidentally let the nitrates get too high. There was about a week between 80+ and then 160+. didn't test nitrates in between. . Which clearly was a mistake.

We did two 50-60% water changes within 3 days.

Now we have ammonia (currently 2ppm, dosed it to about that last night) 0 nitrites and 80ish (at least) nitrates. Last night nitrates was around 20 after a 3.5g water change.

What may have happened? What should we do? Drain it all and refill?

 

[irdajoh]

Small tank are hard to keep stable. Changing the water dosent affect the cycle as long as it dosent dry out your filter media or substrate. I have a 2g tank foe quarantine with some old media in it but I haven't even tested it once. I just replace tell water with main tank water if a fish needs to go in. What you might need to so is lower your ammoina dose. Large amounts can stall the cycle.

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[dragon14]

That's what we were afraid of (smaller tank being harder). We've been dosing to around 2ppm, what do you suggest, maybe a bit over 1?

 

[Mebbid]

That's what we were afraid of (smaller tank being harder). We've been dosing to around 2ppm, what do you suggest, maybe a bit over 1?

High trates arent going to stall the cycle.

How much ammonia were you processing daily before?

 

[dragon14]

About 1.5-2ppm every two days.

We did a full water change basically two days ago. Added ammonia. Didn't check after.

Today ammonia .25-.5ppm nitrite 0 nitrates 40-80. I may have messed up the drops from bottle #2 on the nitrate test tho. They wouldn't squeeze out and then some dropped off the side of the tube. I think I got the 10 drops though. I'll have to test it again tomorrow.

I added a 1/4 tsp ammonia after testing today.

Frustrating

 

[PB_Smith]

About 1.5-2ppm every two days.

We did a full water change basically two days ago. Added ammonia. Didn't check after.

Today ammonia .25-.5ppm nitrite 0 nitrates 40-80. I may have messed up the drops from bottle #2 on the nitrate test tho. They wouldn't squeeze out and then some dropped off the side of the tube. I think I got the 10 drops though. I'll have to test it again tomorrow.

I added a 1/4 tsp ammonia after testing today.

Frustrating

What happened is the ammonia got converted to nitrite and the nitrite got converted to nitrate, exactly what you want to happen, so what's the problem?

Quite frankly I wouldn't worry about nitrates at all when cycling except as an indicator that the BB are working.
If you are getting high nitrate readings, that would suggest that the tank is cycled, or almost done.

nitrates are probably the most worried about, yet one of the least harmful water quality parameter.

Doing a complete water change is very counterproductive when cycling, unless the ammonia or nitrite is way off the charts.
Best thing to do is LEAVE IT ALONE FOR A FEW DAYS.

 

[dragon14]

Thanks PB! I am concerned thought that the ammonia readings are not going down.... they go down slowly, and the nitrates SKYROCKET after a water change, which is weird. But that is normal for a tank that is almost cycled?

I mean we did a 100% water change basically two days ago and the nitrates are between 40-80 already.

 

[ppo8820]

The whole cycling thing is really a pain in the rear. I just wanted some nice tanks, with healthy plants and fish. Now I am sitting here, about 2 months in with 3 tanks. the 5 and 10 are nearly finished and I am fish in cycling since I didnt know better.

My column tank, which is my favorite has been at the high nitrite phase for 3 weeks and it aint moving. I am getting so restless and irritated. I feel like I am in groundhog day.

 

[PB_Smith]

Thanks PB! I am concerned thought that the ammonia readings are not going down.... they go down slowly, and the nitrates SKYROCKET after a water change, which is weird. But that is normal for a tank that is almost cycled?

I mean we did a 100% water change basically two days ago and the nitrates are between 40-80 already.

have you tested your tap water for nitrate?
mine comes out of the tap at 20ppm of nitrate

but if you are adding ammonia, then ideally you should see nitrate rising.

 

[dragon14]

I have but not in a few months. I tested it when we started fish keeping.

But after a water change it'll be 10ish and then the next day or two go up. If it was in my tap, wouldn't it show right away when testing the tank? I'll test it again but I don't think it's my source water.

 

[PB_Smith]

I have but not in a few months. I tested it when we started fish keeping.

But after a water change it'll be 10ish and then the next day or two go up. If it was in my tap, wouldn't it show right away when testing the tank? I'll test it again but I don't think it's my source water.

So it is doing exactly what it should be indicating that the bacteria colonies are established.
Next step is just a matter of how long it takes from the time you dose ammonia till there is no trace of nitrite. If it can process it in 24 hours or less, you are good to start adding livestock.

Ignore the nitrate reading for now and it continually rising as waste (ammonia) is broken down is exactly what you should see.
It sounds as though you are just about done with the cycling process.

 

[aqua_chem]

Every 1 ppm of ammonia you add is converted to about 4 ppm of nitrate. The more you add, the more accumulates. The chemotrophic bacteria that convert ammonia can last weeks without additional ammonia, so there's very little reason to add any on any more than a monthly basis, biweekly at the most. Letting nitrate accumulate like that is just looking for complications. If you're worried about it, I would WC it down to baseline, and redose to 4 ppm ammonia once to see what happens.


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[dragon14]

So it is doing exactly what it should be indicating that the bacteria colonies are established.
Next step is just a matter of how long it takes from the time you dose ammonia till there is no trace of nitrite. If it can process it in 24 hours or less, you are good to start adding livestock.

Ignore the nitrate reading for now and it continually rising as waste (ammonia) is broken down is exactly what you should see.
It sounds as though you are just about done with the cycling process.

Well, the nitrite is 0 all the time lately but the ammonia stays, drops slowly. today the ammonia was around 1ppm. I am leaving it alone and testing tomorrow. I wouldn't be so puzzled if the nitrite was reading something.

should I just wait for the ammonia to read 0 then dose again? I have been aiming for around 2ppm.

 

[dragon14]

Every 1 ppm of ammonia you add is converted to about 4 ppm of nitrate. The more you add, the more accumulates. The chemotrophic bacteria that convert ammonia can last weeks without additional ammonia, so there's very little reason to add any on any more than a monthly basis, biweekly at the most. Letting nitrate accumulate like that is just looking for complications. If you're worried about it, I would WC it down to baseline, and redose to 4 ppm ammonia once to see what happens.


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Thank you for the information.

 

[militantpotato]

If the ph falls you will stall a cycle, which can happen easily in a small tank. It should stay over 7.0 while cycling, which will likely require a handful of water changes semi regularly, depending on the buffering capacity of your tap water.

My opinion is nearly every stalled cycle is from a ph crash or an over dosing of ammonia. The former likely happened to you.

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[dragon14]

the ph was fine, but I will check again, thank you

today after not checking for 4 days, ammonia was .25, nitrite 0, nitrate 80ish.

yeesh. I added some ammonia and will see what is happening tomorrow!

 

[militantpotato]

Look to be about done, congrats! your fish will thank you.

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[dragon14]

Thanks I hope so.