Very concerned about new tank chemistry!

[Ashlimarie83]

I have been cycling my tank now for about 2 weeks now, and I know it's still in its cycling phase, but the last time I checked about 4 days ago, the chemistry was looking like they were getting good, but now my readings are terrible!

My Ammonia is at least 2.0 ppm
Nitrites at about 2.0 to 5.0 ppm (hard to tell, very purple!)
and Nitrates somewhere between 20 and 40 ppm!

I thought everything had settled down a bit, but about two days ago I noticed my duckweed colony dying off rapidly, seemingly for no reason! Now my substrate is littered with little pale dead duckweed leaves (probably a high contributing factor to the ammonia?). I've been trying to scoop it out, but it flits away from me. I'm going to try and vacuum it this evening.

My other plants seem to be okay I guess, one is budding so it looks happy, and my danios are...well they're danios.

Any solutions or am I just over-worrying and this is a normal spike?

 

[auntiejude]

Yes, dead plants can cause ammonia spikes. But it's not necessarily a bad thing, as it contibutes to the cycle.

However, if you've got fish in there you need to get the ammonia and nitrite down. The plants will be absorbing some of the nitrates, but the ammonia and nitrite are at a toxic level and you need to do some water changes.

You also have to remember that your bacteria will not cope well with fluctuations in ammonia, and may not be able to deal with a sudden increase. If you have enough bacteria to clear 1ppm in the tank and you suddenly spike at 3ppm your bacteria can't clear the other 2ppm and it builds up.

 

[Ashlimarie83]

Yes, dead plants can cause ammonia spikes. But it's not necessarily a bad thing, as it contibutes to the cycle.

However, if you've got fish in there you need to get the ammonia and nitrite down. The plants will be absorbing some of the nitrates, but the ammonia and nitrite are at a toxic level and you need to do some water changes.

You also have to remember that your bacteria will not cope well with fluctuations in ammonia, and may not be able to deal with a sudden increase. If you have enough bacteria to clear 1ppm in the tank and you suddenly spike at 3ppm your bacteria can't clear the other 2ppm and it builds up.

Alright I'll try to do a good water change today and vacuum as much of the dead matter as I can.