# high nitrite



## laxfanweeb (Mar 2, 2011)

okay my 20 gallon tank has unusually high nitrite levels. the nitrates are almost at 0, the ph is perfect at 7+ and i tested the tap and nitites are 0 out of the tap. the only deaths in the tank were a school of 7 spotted cory cats and a pleco when the power went out and caused a change to the water almost immedieately paticularly the temp causing them to stress and all died within hours of each other. i did have two ghost shrimp which were about a year old and i just found one dead and can't find the other so i am guessing he is dead somwhere but i doubt one dead ghost shrimp is causing a nitrite level of 5. i just vaccumed the gravel two days ago and the water is crystal clear as i change it about 50% twice a week. any ideas? is it possible that the filter could have a brown algae colony and it's being spread throughout the tank?


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## NeonShark666 (Dec 13, 2010)

A high Nitrite level indicates your tank is still cycling and/or is polluted. With your Spotted Corys your tank would have been over crowded. Both Shrimp and Corys don't like high Nitrites and, of your fish, would be the first to die. If you can check for Ammonia. Don't feed your fish for a few days and see if your Nitrites increase. If so, you have decomposing organic matter in your tank and you need to find it.


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## jrman83 (Jul 9, 2010)

Why is a ph of 7 perfect? Why do people think that? As I posted in your other thread, something tells me something was going on long before your filter stopped working for a little while. Not long enough to drive nitrites up without a corresponding ammonia spike. I believe the issues you see now have nothing to do with the filter and were present before. If a death made you think to test and you don't test often with that many fish, who knows? A cylcing tank would explain it.


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## laxfanweeb (Mar 2, 2011)

when the corys were alive the nitrites were fine the brown algae started after them. the spotted corys died like a month ago. my bamboo shrimp are thriving they feed like crazy at night. they just come out and do their fan dance. one just molted yesterday actually. since i got him he has gotten a good bit bigger and has turned bright red like a lobster and has a huge thick whit stripe down the middle. i got them when the spotted corys died but they don't do near the job the corys did. i just added three albino corys and i will be moving my guppies i think.


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## laxfanweeb (Mar 2, 2011)

as for the ph of 7. everything i have in that tank should be in a tank with a ph of 6.8-7.2 that's why.


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## jrman83 (Jul 9, 2010)

Is your ph 7.0 or close to, out of your tap?


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## laxfanweeb (Mar 2, 2011)

thank you jrman it is close to 7.0, it's actually just higher. i did a major change in the tank and the problem seems to be going away i just can't figure out exactly what caused it.


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## phys (Feb 4, 2011)

Thats strange that you would have a nitrite spike. did you clean the gravel before or after the spike? if you did it before, you may have had some pockets of it in your tank somewhere and you released that. Otherwise, you may have had something dying somewhere or decomposing somewhere.


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