Late cycling questions

[Aspencer]

Fishless cycle....going on about one month...with a 1 month old seeded filter..semi heavily planted...

For the last 10 days, Ammo has gone from 4 ppm to 0 in 24 hours but the last two days, Ammo conversion to NitrItes have slowed to over 1 day to get to 0.

NitrItes the last two days have gone to just above 0 while NitrAtes are high with no water changes....

Should I just sit tight and keep dosing until Ammo gone in 24 hours and NitrItes are 0?

 

[rich311k]

Your right there now. I would do a big water change, then dose ammonia to 4 and see what happens. You are very, very close.

 

[Aspencer]

Your right there now. I would do a big water change, then dose ammonia to 4 and see what happens. You are very, very close.

ok

 

[rich311k]

I just think that way you reset everything and will get good clean readings. You will know exactly what is going on.

 

[Aspencer]

Your right there now. I would do a big water change, then dose ammonia to 4 and see what happens. You are very, very close.

Big as in 60% water change?

 

[rich311k]

You can do more if you want, no stock in the tank to effect.

 

[eco23]

I agree with Rich that you've hit a stall. I'd do around a 50% pwc and dose it back up.

Have you been monitoring your pH? Do you know what it is in the tank right now?

 

[Aspencer]

I agree with Rich that you've hit a stall. I'd do around a 50% pwc and dose it back up.

Have you been monitoring your pH? Do you know what it is in the tank right now?

I do both test because when I do the Reg pH, it is blue and when I do the high pH, it is light brown so I guess it is 7.4 as is my 10g with the fish I am waiting to move into this tank.

 

[Aspencer]

Well, the last couple of days, my Ammonia has gone down but my NitrItes and NitrAtes have been high and have been doing 60 to 70% water changes.

I have deep sand substrate. I cannot seem to get NitrItes and NitrAtes down.

Today I change 11 gallons of water, remember I have 3 to 4 inches of sand in a 20g long, dosed 2.5 ml of Ammonia.

Tested one hour later, Ammonia around 4 ppm, but NitrItes are deep purple and NitrAtes are deep red...cannot seem to get those down with water changes...Sunday I did 3 water changes...10 gallons followed by 2.5 gallons followed by 8 gallons...mainly because I kept testing and both stayed high.

Any ideas why?

 

[eco23]

So you have done back to back water changes and the no2 and no3 doesn't come down? Very odd. If the levels are way above what the test kit can show, it's possible a 50% pwc wouldn't actually reduce it by half...but with numerous pwc's in a day you'd have to see some major reduction. I couldn't ever imagine it...but have you tested the water straight from your tap?

 

[Aspencer]

So you have done back to back water changes and the no2 and no3 doesn't come down? Very odd. If the levels are way above what the test kit can show, it's possible a 50% pwc wouldn't actually reduce it by half...but with numerous pwc's in a day you'd have to see some major reduction. I couldn't ever imagine it...but have you tested the water straight from your tap?

Yes, but will test right now again.

 

[Aspencer]

Ammonia 0
NitrItes 0
NitrAtes 0

 

[rich311k]

You were almost done, now the nitrites are through the roof again. This is a interesting one.

 

[Aspencer]

You were almost done, now the nitrites are through the roof again. This is a interesting one.

With my sand so deep, do you think that I have trapped NitrItes and NitrAtes and it is releasing it as I change water?

 

[eco23]

Ammonia 0
NitrItes 0
NitrAtes 0

You're using pure ammo, right? My normal suggestion would be to knock out back to back pwc's, but since you've tried that...we'll look elsewhere.

What I'd assume is that you've built one heck of an ammo > no2 bacteria colony, and now we're just waiting for the no2 > no3 guys to catch up. The fact you can chew through that much ammo in a 24 hour period is producing a ton of nitrItes and the nitrifying bacteria can't keep up with what's being thrown at them.

Personally I'd try one last back to back group of pwc's to see if I could knock the no2 down, but my other suggestion would be to pull back on the ammonia for a few days. Just feed it ~1ppm for the next 2-3 days and see if it gives the bacteria an opportunity to begin converting the nitrItes into nitrAtes without having too much more thrown at them.

The good news is your going to have one beast of a bio-filter when this is done

 

[eco23]

Wait...so your no2 had spiked, dropped close to 0 and is now spiking again? I must've misunderstood.

 

[Aspencer]

I am running two aquaclears 50 on the tank with double bio bags, no carbon.

I will plan on seeing where we are tomorrow morning, then do big water change around 6 am and one around 10 am...high school teacher and my prep period is around 10.

Then see what my parameters are.

 

[Aspencer]

Wait...so your no2 had spiked, dropped close to 0 and is now spiking again? I must've misunderstood.

yes, for a few days both Ammonia went down and NitrItes were close to 0. Then NO2 and N03 began to go to untestable levels, Last 2 days.

 

[rich311k]

I honestly would do another water change and then try another nitrite kit, something is just not right here. maybe have an LFS test it for you, ask to actually see the results.

 

[eco23]

yes, for a few days both Ammonia went down and NitrItes were close to 0. Then NO2 and N03 began to go to untestable levels, Last 3 days.

IMO, classic tell-tale signs of a pH crash. When the cycle completes and the bacteria virtually consume all the no2 overnight...they basically let out this giant acidic burp. If the water is low in alkalinity or the bacteria has used up all the buffers in the water...the pH falls ridiculously low. Most people do a pwc before they ever test pH, so they don't even know it happened.

Crashes can result in some bacterial die-off or at the very least become dormant for some time depending on how low the pH fell. The crashes seem to only affect the no2 to no3 bacteria...and it takes time to recover.

You'll just have to consider your cycle rewound a bit...and keep a super close eye on the pH as you continue to go. If you see even a hint of the pH falling...break out the bucket and bottle of Prime.