Tank Cycling Question

[mcolangelo]

Looking for some opinions regarding my cycle and ammonia readings.
I've been out of the hobby for a few years but diving back in head first.

I got a 180g full reef setup from someone leaving the hobby on 06/21/25
Running tank was tore down. Most of the LR and all the fish and coral were transported fully submerged. Sand went into a 5g bucket and was sealed.
Got everything home and immediately transferred all the coral, some of the LR, and fish to a 55g holding tank with fresh SW. Dosed it with a capful of prime on 06/21,06/24, and 06/27.

I was not able to test Ammonia or Nitrate until 06/28 and the results were.
Ammonia: 0.5ppm
Nitrate: 5ppm
Nitrite: 0ppm

That tank has stayed at that level. I have not performed any water changes (yet).
It looks great, all the coral, fish, and anemone seem to be thriving. -- I think this tank is fine. But I'm confused why I've got 0.5 ammonia.


The main 180g tank is where it gets a bit more complicated.
A bunch of the rock was left for days in the SW brute bins and started to stink and eventually developed a strong sulfur smell and rock took on a blueish-black appearance. But I saw some bristleworms still moving around in bottom of the can despite being cold and stagnant water.

06/27 - I setup the 125g sump. Removed the rock from the stank water and rinsed thoroughly in fresh water then it went into the refugium chamber with a strong powerhead. I ran carbon and skimmer. Within 36 hours the water was clear and the smell completely gone.

06/28 - I setup the 180g tank. I drained the green nasty water from the 5g sand bucket. It smelled terrible. I added that stinky sand to the 180g tank along with 4 new 20# bags of carib-sea arag alive. Moved the rock from the fuge into the tank too. Added a powerhead to the main tank and ran it. Dosed it with appropriate amount of Prime.

By 10pm 06/29/25 the sulfur smell was gone and the tank clear. But, like the 55g holding tank, ammonia is reading 0.5ppm, Nitrate 5ppm, Nitrite 0ppm.
Today the tank looks great minus the glass needing to be wiped clean.

I wanna move everything from the 55g holding tank over to the 180g tank as soon as it's safe and "ready" (and after I do a little more cleanup and a small water change)... but the ammonia reading is kinda confusing me. I think I skip cycled both tanks but I guess I'm surprised considering how nasty both the sand and rock was when I added it to the main tank. The skimmer was really going nuts as well but it's calmed down now too.

Any suggestions?
Thank you!

 

[Fish Fan]

Welcome to Reef2Reef!

I bet you're likely using the API brand test kits, and those are known to often show 0.25-0.50 ppm for ammonia when it's likely much less. Your 55 gallon sounds like it's fine, the 180 may be set back by the freshwater rinse. I would stop adding Prime, and just let it cycle on its own. The Prime isn't really effective at removing ammonia like it claims, and it can also show as ammonia on an ammonia test, further complicating things.

Good luck!

 

[mcolangelo]

Yes, API for Ammonia.
I debated rinsing the rock. It was in stagnant saltwater for about 5 days though with a gelatinous mass floating on top. So i gave all the pieces a quick dunk hoping to rinse them of at least some of the nastiness.

Only reason I’m in a hurry to get everything out of the 55g is because it’s so cramped and not everything is playing nice. I also have a few coral in a 20g tank as well because I ran out of room in the 55.

 

[Fish Fan]

Your larger tank may be good to go, I don't believe the freshwater dunk would completely and instantly kill all the bacteria. I think many likely survived. I'm concerned that this is a test kit error showing ammonia when it may be a lot less. Can you bring a sample to your Local Fish Store and see if they can test it for you?

 

[Randy Holmes-Farley]

I agree it is probably cycled, but if you want to convince yourself, boost ammonia to 2 ppm and observe the drop again. 0.5 ppm may just be test error, and is not a concern anyway.

 

[mcolangelo]

Your larger tank may be good to go, I don't believe the freshwater dunk would completely and instantly kill all the bacteria. I think many likely survived. I'm concerned that this is a test kit error showing ammonia when it may be a lot less. Can you bring a sample to your Local Fish Store and see if they can test it for you?

Only legitimate LFS that I would trust is an hour away with weird hours. There is a Petco nearby but they’re probably using the same API kits they sell.

I considered ordering a Salifert Ammonia and Nitrate test, that’s the brand I use for everything else (Kh, Ph, Mg, Ca, PO4). But I cheaped out last minute and grabbed the API kit.

I probably won’t be migrating anything from the 55g to the 180g for another week or so. I’ve got about 85lbs of dry/dry-ish rock also acquired during the trade that is currently bleach curing. I’m thinking that will go in next (this weekend). I’ll monitor a couple more days and then start slowing migrating stuff from the 55g to the 180g.

There is some gha and aptasia in the 55g that I’m gonna try to deal with the best that I can during the migration as well.

This has certainly been quite the adventure lol.