Can plants cause nitite spike...

[Rowangel]

Can adding plants to a tank cause a nitrite spike or a mini cycle? Here is what I did; I changed out my already cycled 10g into a tank for puffers and a leaf fish by moving the old fish to community tank, doing a 30% water change and then adding new fish into the 10g. No problem there, all parameters good to go. A couple days later I added plants. The following afternoon the puffers looked a bit in distress-hanging around the surface and so on. I tested and everything was fine but the Nitrites which tested at 1, Yikes! So I quickly did a water change and have been doing them everyday for three days now. Yesterday the nitrites spiked so bad I decided to removed the fish and set them up in my community tank (in a large breeder net) temporarily until I can figure out what happened. Can plants do this or did something else happen?

 

[EcoPit]

If the plants are dying they could cause it, but not in a fully cycled tank. You tested ammonia and nitrites before adding the plants and they were both zero?

 

[Rowangel]

Yup, everything tested 0 before I added the plants (both before and after the 30% water change) and the new fish were doing well. I didn’t notice anything suspicious until after adding the plants… Should I just treat the tank as a cycling tank and start over? Will I have this issue again if I buy more plants?

 

[EcoPit]

I would guess that something is giving off large amounts of ammonia which is being converted into nitrite, but you don't have enough of that particular bacteria to convert it all on to nitrate. Or those bacteria were killed off for some reason. When you did that 30% water change was it not fully dechlorinated, or was it a vastly different temp? But that couldn't be it because the nitrite didn't show up after the fish were added, it was after the plants were added. So, where is the ammonia or nitrite coming from? Are the plants doing well, or are they dying?