Questions on mini cycle (4 gallon pico)

[SchnauzerFace]

Hi everyone,

I've had a 4gallon pico set up for about 6 months. It cycled just fine but before I could start stocking I got majorly sidetracked with work (and our 75 gallon reef!). I kept the water flowing and topped off every night, but I didn't do any other maintenance.

I'm finally ready to refocus on the pico, so on Saturday night I did a major clean. I changed the sponge and carbon filter in the media basket, did ~100% water change, and soaked the HOB filter and power head in vinegar for a deep clean.

This was less than 48 hours ago. I checked the levels just now and I'm appearing to have a mini cycle.

Ammonia: .25
Nitrite: 0
Nitrate: ~60

Should I wait for ammonia to drop, or should I do a big water change now? This cycle seems to be progressing awfully quickly, isn't it? Given that I did about 100% WC two days ago, I'd expect the nitrates to be near 0. How long can I expect this to last? All that's in there is a 2" sandbed d & about 4 lbs live rock.

Thanks in advance!!
Andrew

 

[Whys Alives]

You're telling me your nitrate levels went from zero to 60 in 48 hours? No... that doesn't sound right.

What ever the case, the point of doing a water change is to reduce either ammonia, nitrite, and/or nitrate. Why would you wait for ammonia to drop before doing a water change? That's the point of doing a water change.

 

[SchnauzerFace]

You're telling me your nitrate levels went from zero to 60 in 48 hours? No... that doesn't sound right.

I agree 100%, which is why this is such a weird cycle. It's not following the usual cycle pattern, and it shouldn't have spiked that much that quickly. But I should point out that I didn't actually do a nitrate test immediately following a 100% WC, but my guess is that it would have been at or around 0 (assuming the new water was free of nitrates, which it was).

What ever the case, the point of doing a water change is to reduce either ammonia, nitrite, and/or nitrate. Why would you wait for ammonia to drop before doing a water change? That's the point of doing a water change.

If the tank is cycling like a new tank would, then there are arguments for NOT doing water changes and letting the tank's chemistry even out before doing water changes. If the tank is recycling, by pulling out the water I may be delaying the process of re-seeding the tank with beneficial bacteria. Since this is unlike any situation I've come across before, I was looking for helpful advice.

 

[Whys Alives]

I agree 100%, which is why this is such a weird cycle.

No, my point isn't that it's a weird cycle; my point is, it's not possible. Check your tester.

If the tank is cycling like a new tank would, then there are arguments for NOT doing water changes and letting the tank's chemistry even out before doing water changes.

You said it's been 6 months, no? Your tank finished cycling months ago.

 

[SchnauzerFace]

No, my point isn't that it's a weird cycle; my point is, it's not possible. Check your tester.


You said it's been 6 months, no? Your tank finished cycling months ago.

In a 4gallon tank, I can imagine I stirred up a lot of buried junk in the substrate. With such a small water volume it wouldn't take much for nitrates to go crazy. But the tester is reading my 75gallon at ~5ppm, which is where it's been for a long time.

Can a major upheaval (such as a 100% WC and deep cleaning of equipment) not cause a mini-cycle? I read about mini cycles happening all the time.