I feel incredibly dumb but I cannot figure out if the ammonia reading is 0 or 0.25 ppm. It's not yellow but not quite greenish either. It's this yellow with a baby touch of green?? I want to do a water change if it's .25 but I really can't tell! If it were 0 would it be truly a clear yellow? I've got a 0 nitrite reading and 15-20 nitrate reading.