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Sudden nitrite spike, please help urgently!

Subject: Sudden nitrite spike, please help urgently!
by whiteysar on 7/10/2013 18:36:26


I have done a mid week water test as fish gasping at surface which is very out of character. Have found a considerable nitrite spike and don't know for sure the cause...please help!

Juwel rio 180 tank fully cycled, one black moor and one fantail added in August
No changes except new aquarium plants a few days ago. Have since been advised here that plants may be unsuitable and I wonder if they have caused the problem.
Also had a small issue of fin rot due to injuries through playing in the tank. Interpet fin rot treatment added last Tuesday and virtually no evidence of this remains.

Nitrate - 20
NitrIte - 1ppm ......aaaargh!
Ammonia - very slight

Will be doing the water change shortly and removing 'suspect' plants.

Any other help / advice please? ! Fish almost always at surface :( :( :(