10 gallon, high nitrite?

Question
Hello, I have had some problems with my 10 gallon tank going through the Nitrogen cycle. My tank had an extremely high ammonia level, which was gone a week later, but was replaced by nitrite that was off the charts. My fish are breathing very hard and tend to stay middle to top, although its not too much different than normal. My fish are 3 guppies, about an inch each (I added 3 ghost shrimp, i removed the two that died, one is still living). 2 males, one female. I had moved them from a 2.5 gallon because the female had babies and just recently had maybe 15 or so. I have done many water changes, but with no luck. I reduced my feeding, and nothing changed. Also as a side note, my filter has a clear thin film that sticks to the side and floats on top of the water as it exits the filter. I do not know what this is, but it may have something to do with this, so I added it. Also, one of my fish has a dark brown tail, which I have read about and seems to be nitrite poisoning. If you could help, I would greatly appreciate it. Thanks.

-More details can be found at http://answers.yahoo.com/question/index;_ylt=ApVAMJn4lNTXyn6quvOfUWjsy6IX;_ylv=3... if needed. Just didn't want to make too long of a question.

Answer
Hi Chris,
Your tank is currently "cycling" which is normal and usually last about 4 weeks after first initial tank setup.  Theres a type of bacteria that breaks down Ammonia into nitrIte and another set of bacteria that breaks down nitrIte into nitrAte.  When you see readings of nitrAte, it shows that your tank has finished cycling.  From the looks of your tank it shows that the tank has only finished growing 1 set of bacteria and the other is still pending.  Remember to tell us what "high" is.  1ppm might be high to one caregiver and 5ppm might be higher to another.  Try to keep the nitrIte level below 1 if you have fish because long term nitrIte will indeed cause health problems later down the road.  Give it time and it will eventually cycle.  But during this time since you have fish, reduce the nitrIte level by doing water changes and keep doing water changes until you see readings of nitrate.  To accurately read this readings, use liquid testing rather than test strips because it will be hard to read small nitrate readings with all the water changes.

Hope your fish the best of luck.
-Matt-