Tank cycling without obvious ammonia source

[m3rcfh]

Hey guys, I was looking to get some opinions from the more experienced/pros, as I haven't cycled many tanks on my years on this hobby.

I'm taking my time and upgrading to a bigger tank and I had the chance to place it side by side with my current tank, so both of them are running in parallel. As I intend to move everything from the small to the big/new one and get rid of the small, I moved 5 days ago about 30% of my live rock from old to new plus a cup of sand to seed it.

Yesterday I was planning to get the cycle started with pure ammonia, so I tested the water before adding any chemicals. For my surprise the ammonia level was at 0.25ppm (which I'm assuming to be coming from decaying matter on the live rock), 0ppm nitrite and 0ppm nitrate. Decided to boost the bacteria adding a bottle of Dr Tims One and Only (just in case, working or not, adding more bacteria to the system can't be bad). Checked this morning again, ammonia level rose to 0.5ppm and no nitrites/nitrates just yet.

Is my tank going through a cycle by itself only using the ammonia generated by the stuff that got stirred up/died when I moved the live rocks over?
If yes, as soon as the ammonia level lowers to 0 and nitrates start to show up, am I safe to add fish or should I add 1ppm of pure ammonia to check of really went through a cycle?

Honestly I didn't think it would get a full cycle started just by seeding it with live rock/bit of sand, without adding any obvious/certain source of ammonia.

Thanks in advance!

 

[m3rcfh]

Also, I plan to transfer the fish from the old tank slowly... 2 clowns at first, 2 chromis afters week or so with the euphylia corals + some more live rock and and after 3 weeks or so a tang and the remaining soft coral... I think that's not too slow but the addition of more live rock should help

 

[m3rcfh]

Alright just tested for ammonia again, still at the same levels. I guess it isn't cycling yet

 

[Big G]

Alright just tested for ammonia again, still at the same levels. I guess it isn't cycling yet

It's probably at the same level because of the Dr. Tim's. If you hadn't added it, the levels would have increased. I'd be patient and watch for the ammonia to drop in a couple of days.

 

[DLHDesign]

Is my tank going through a cycle by itself only using the ammonia generated by the stuff that got stirred up/died when I moved the live rocks over?

Most likely; yes. Detritus and die-off of organisms as a result of the move (without a large enough bacterial presence to consume it) could certainly account for the ammonia you are seeing.

If yes, as soon as the ammonia level lowers to 0 and nitrates start to show up, am I safe to add fish or should I add 1ppm of pure ammonia to check of really went through a cycle?

The check ensures that you have enough bacteria to support whatever you add in. It's always a good idea, but others have had success without performing the test. I'd run the test, myself - especially because it's a day or two we're talking about.

Note that moving over new live rock could trigger the same thing as you are seeing now (eg; restarting a new "mini cycle"). You'll have a more established tank at that point, so you may not notice anything (ideally), but I would suggest moving over as much as you can before adding any fish and monitoring the levels for a day or two, at least. Your existing sand most likely contains enough bacteria to support your current tank for a time, so you might even consider moving it sooner.

 

[m3rcfh]

Thanks guys, that really helped me confirm my suspicions and learned new things about upgrading and cycle with the seeding method - best part of the hobby is that you really learn something everyday.

Major takes I have from the upgrading experience, please correct me if I'm wrong: Dr. Tims One and Only indeed works, but not in the way I have seem people claiming it does. It doesn't magically transform the tank in a healthy environment for fish, but rather helps boosting the cycle; and that simply moving stuff from an old established tank to a new one does not result in an instantly cycled tank (as many posts out there recommends people to do), unless it's an emergency... the live rock did start a cycle even when literally stayed out of water for only a few seconds

 

[Big G]

It appears that Dr. Tim's, Bio Spira and other similar products quickly "cycle the water" but not the tank. The water has the good bacteria, but the tank, rock, sand, filter, etc. have not built up a sufficient "cycled" condition in the overall tank, IMO, which takes time. That's why a small bio-load, initially is a good idea in a Dr. Tim's, etc. dosed tank.

 

[DLHDesign]

It doesn't magically transform the tank in a healthy environment for fish, but rather helps boosting the cycle

Correct. And that's not nothing - boosting a cycle can sometimes mean the difference between days and months waiting for a tank to be ready.
The goal of cycling a tank is to build up a large enough population of beneficial bacteria that any waste produced by the life in the tank can be converted into harmless (or even beneficial) chemicals. As such, there isn't a single answer for when a cycle is complete - the build-up of beneficial bacteria will continue until such time as the food source(s) and bacterial volume are equalized. Bacteria are small, but there's no practical way that you could fit enough of them into a bottle meant for retail sale to fully populate a reef tank - not even a small one. The best that can be hoped for is that the bottle (or bottles sometimes) can act as the seed - sort of like being able to start at the "Mile 1" marker instead of the start line in a race.

the live rock did start a cycle even when literally stayed out of water for only a few seconds

It likely wasn't the time out of the water that did anything (or not much of anything). The ammonia more likely came from the loosening of detritus and debris that was stuck on and/or in the rock. Moving the rock shook it loose. Once it was shaken loose, it started to break apart and degrade faster than it would have were it still sitting undisturbed in the original tank.
I honestly don't know if it would have helped to rinse off the rock during the move... One the one hand, you could have rinsed off some of the detritus that broke down in the new tank, but on the other you may have (likely would have?) rinsed off some of that very bacteria you were hoping to bring along...

I'm going to be moving in 6-7 months and will be upgrading my tank along with the move. One of the things I've been researching is this very topic - how to move a tank (in my case; move it into a new house an hour away and not across the room). I think I may run an experiment before the move day:
Fill three of my QT tanks (10gal breeders) with fresh-mixed salt water. Measure out three equally-sized rocks from my sump (where I have spare rock). Remove one measure and directly transfer it into one of the tanks. Rinse off another measure using tank water, and the third measure rinse with tank water and add a bottle of Dr. Tims. Monitor the "big three" of the cycle in all three tanks until all three reach a point of equilibrium...
The wife is going to LOVE having three QT tanks in the house filled with just rock, I'm sure... ;-)