I tested my FC and thought the number was a little low. For the heck of it, I tested again and got a higher number, then tested again and got a number in between the two. I'm using a TF-100 Test Kit and testing at 10ml. My CYA is around 60 and I'm trying to finish my SLAM by keeping FC at 27. I'm now in the OCLT and even that 1ppm makes a difference so I can stop testing so much. I need between 45-55 drops at a time. Anyone?