Unusual Cycling Issue

[cajungrl81]

I have a 10g planted tank with AC30 filter It had been cycled and running ok for about a year. In early December, the tank experienced a pH crash which stalled out my cycle. On the direction of my LFS & several others, I did multiple water changes to restore the pH...which in theory should have restarted the cycle.

However....

The ammonia will spike, sometimes as high as 2 ppm...then drop as low as .25 ppm...then spike again, and so on. As I understand it, once the cycle begins converting ammonia to nitrite and nitrates, the ammonia level should fall and KEEP falling...? Yet there's no sign of nitrites or nitrates, and ammonia levels are fluctuating every which-way with no discernible cause.

Short of breaking down the aquarium and starting over to purge it of some unknown contaminant, I'm at a loss of what else to try. Or even why my cycle (or lack thereof) is doing what it's doing.

Meanwhile, the fish from this tank have been confined to quarantine...and are very stressed out.

Readings since about midway through the pH debacle follow.

HELP!



12/15/2015 6.4 2 0 0
12/16/2015 6.6 1 0 0
12/17/2015 6.6 0.5 0 0
12/19/2015 6.6 0.25 0 0
12/21/2015 6 2 0 0
12/22/2015 6 0.5 0 0
12/23/2015 6.4 2 0 0
12/24/2015 7.4 0.25 0 0
12/26/2015 7.4 1 0 0
12/28/2015 7.4 0.5 0 0
12/29/2015 7.4 0.5 0 0
12/30/2015 7.4 0.25 0 0
12/31/2015 7.4 0.5 0 0
1/3/2015 7.4 1 0 0
1/4/2015 7.4 0.25 0 0

 

[Delapool]

Hi, how did this turn out?

Was wondering if you had checked the tap water used in water changes for all readings eg make sure no ammonia in there.

Also

 

[cajungrl81]

Turns out, the city chose the same time as the initial pH crash to do its annual chlorine flush...which raised the chloramine levels in our water to several times what the standard dose of Prime can handle. Ended up having to triple-dose. Looks like everything is finally getting back to normal. Fingers crossed.

 

[Delapool]

Ouch! Good luck with it.