Ammonia stuck at 1 ppm

[DFandango]

Hi everyone!

I’m currently on day 9 of cycling my new reef tank and would appreciate some advice.

Here’s my setup:

• Dry rock
• Ocean Direct Live Sand
• AF Life Bio Fil
• Added ARKA Special Blend immediately after setting up the tank
• Dosing Seachem Stability daily

Unfortunately, I initially used a faulty test kit, which resulted in me overdosing ammonia without realising it. When I eventually tested with a working kit, ammonia was reading around 5 ppm.

Over the following few days, ammonia gradually dropped. Initially, 5 ppm, a few days later 2 ppm and currently 1 ppm

My current parameters are:

• Ammonia: 1 ppm
• Nitrite: 0.25 ppm
• Nitrate: 1 ppm

Weird thing is that these readings haven’t changed for the past three days.

My questions are:

1. Could the initial high ammonia concentration (around 5 ppm) have killed off some of the beneficial bacteria or inhibited their growth, slowing down the cycling process?
2. Is it normal for the cycle to stall at these readings for a few days?
3. Would you recommend doing a partial water change to bring the ammonia level down, or should I leave the tank alone and let the bacteria continue developing?

I’d rather avoid interfering with the cycle unnecessarily, but I also don’t want to risk damaging the bacteria.

Any advice or personal experience would be greatly appreciated!

Thanks in advance!

 

[Mr. Mojo Rising]

A dry rock cycle takes about 3-4 weeks. Its just a waiting game for it to come down to zero.

 

[Randy Holmes-Farley Verified Community Expert]

How are you measuring ammonia?
If it really dropped from 5 to 1 ppm then stopped, it may be test error, not actual ammonia.

But I'd keep watching a bit longer

 

[Decamicron Labs Verified Sponsor]

I'd just wait it out to be honest. A 4 ppm reduction in ammonia corresponds to ~13ppm nitrates, so I am guessing there may be some error in one of your test kits.

5ppm is known to slow down nitrifiers, but I wouldn't do a water change at this stage simply because the headache of figuring out which test is wrong will be more of a headache than its worth. If you want to speed things up I'd ask your local LFS for some rubble or an old filter to help seed your tank instead.

 

[Bmaytime]

Patience, I just went through the same thing. Ammonia didn’t drop for me until week 3, then another week my nitrites dropped.

 

[DFandango]

A dry rock cycle takes about 3-4 weeks. Its just a waiting game for it to come down to zero.

Slow and steady always wins the race! Will for sure wait a bit longer but I’m always curious to find out how this happens

 

[DFandango]

How are you measuring ammonia?
If it really dropped from 5 to 1 ppm then stopped, it may be test error, not actual ammonia.

But I'd keep watching a bit longer

Testing with Colombo tests. First used Salifert for the ammonia but could not get a reading on any ammonia for the whole cycle. Tested the 5 ppm immediately after getting the Colombo one. Rinsing everything with RODI before and after tests.

The drop from 5ppm to 1ppm happened over the course of a few days with a measurement of 2ppm in between. So I hope I can assume the test is to be trusted. Weird thing is I’m not seeing a matching rise in nitrites but I do see a rise in nitrates. Tested the RODI water as well, came out at 0 for all 3 parameters. I’ll definitely ride it out till zero! Just curious to see if these patterns/stalls are more common when cycling with dry rock

 

[Randy Holmes-Farley Verified Community Expert]

There will be some consumption of the N as well, so one does not always see a rise in nitrite or nitrate. Also, some bacteria products are not nitrifiers, but rather heterotrophic bacteria that will simply take it up 9which is OK, and may well be why some products are faster than others).

 

[DFandango]

Okay, so to add to the story… All of this had me thinking about what else could potentially be wrong with the tank, especially since I got it second-hand.

While setting it up, I noticed that the previous owner had siliconed a ring to the back wall, which was connected to the return pump. I didn’t think much of it at the time, but today I decided to message him and ask which silicone he had used. Turns out it was bathroom silicone containing anti-fungal chemicals.

Could this potentially have been preventing the beneficial bacteria from establishing properly?

I’ve since removed all the silicone, done a large water change and added some carbon, just to be on the safe side. Glad I caught this before adding any livestock! Could’ve gone on for ages without me ever noticing hahaha.