Interesting cycle.

[echoofformless]

So I've a 29g FOWLR tank that has been running for a little more than three weeks. Half of the rock was pretty much cured at purchase (Fiji) and the other hald uncured (totoka.)

The ammonia level has been steady (just below .25) for the entire time and nitrite was very slight until it dropped off last week to zero. No nitrate was present until last week. It is now at around 5 or so.

But the odd thing is that tonight's test indicates ammonia at above .25. Maybe almost at a .5. But no nitrite to be found.

I'm finding this slightly confusing. Nothing has changed to cause an ammonia spike. All of the rock looks the same as it was. I haven't added new creatures or noticed any more die off on the rock.

I'm not sure if I should do a water change - wouldn't that affect the cycle and set me back? Or should I do a small one maybe?

[The Zigman]

any water changes?

[echoofformless]

haven't changed the water since starting the tank.

[Reefscape]

Hmmm...To be honest, i dont think your really experiencing a proper cycle, which may be due to the rock used...The slight increase in ammonia could easily be caused by something inside a crevice of the rock dieing off....Just because you cant see it, dont mean it aint there kind of thing....

[Catpicklesdog]

I had a slight ammonia spike when I upgraded my tank and was using fully cured rock. I'd let it run another week without a water change to see how it does. If the ammonia has then come down, do a water change. Like Reef said, it's probably due to some die off.

[echoofformless]

Sounds like a good explanation. Thanks guys.