Water Holding Tanks

[DiscusKeeper403]

I did a 25% water change on my tank tonight, with aged water from my holding tank. Since there was a little bit of water left I decided I mine as well test water parms in the holding tank. Ammonia 0ppm, Nitrite .25 ppms!!! The fish seemed fine, I tested the aquarium and both 0 for ammonia and nitrite. I did another water change with straight tap w/dechlorinator just to be safe. Emptied the holding tank and scrubbed every nook and cranny with paper towel, and refilled it. I did see a bit of debris in the tank, no idea were it is coming from, could it be dust? I have been scrubbing it out once and a while but I am worried now I have been filling the tank with nitrogen rich water How do people keep their holding tanks nitrogen free?

 

[DiscusKeeper403]

Anyone? No idea where the debris is coming from.

 

[smbgpd]

How accurate is the test kit? If the water in the holding tank is a s fresh and pure as you say and there is no obvious source of contamination then you have to suspect the test kit.