the tubing i used is 250 O.D. x .170 I.D here is the link
http://www.homedepot.com/webapp/wcs/...ctId=100057801
as for no change i ment there is not nitrites and no ammonia, but still 40ppm (same as tank) of nitrates comming from it. haven't checked the pH comming from it yet. the flow comming out of the tubing is a fast drip just slower than a stream but still a drip.
i also don't understand why the coil can be too long or why there can be too much media in the chamber -- in other words, how can a denitrator be too big?
why would i get the possibility of low but varrying nitrate levels and not completly all 0?
thanks for the help so far. i have just been battling nitrates for so long i don't know what else to do. lol