Additionally, the drop kits definitely work better than the test strips. A friend of mine using the test strips got a reading of 0 every time he tested...when we tried my APi drop kit we found the actual nitrate level to be between 10-15 ppm.
I use Jungle test strips for daily checking & they work fine, but you have to read the instructions. One dip, then check certain pads at certain times, etc... I use my API drop test kit once a week for more accurate readings & redundancy.
and your driftwood is probly causeing your green tint. It will also give a tea /green color , it will clear up in time. Carbon will help clear it up faster and water changes. Only run the carbon for a week though , then toss it