50% water change and still 20ppm nitrates

[reefwars]

the ideas are never ending thats the best part of this hobby lol so youve always checked your nitrates right there must have been a point where you noticed them going up was it some thing you did think hard anything you changed or added or did it creep up slowly maybe from food or something small over time????? where did you get your rock and how old is it?? i had a problem with very old rock and lowering my nitrates so i did the ol switch er oo