Okay - dumb question, after I've like 5 or 6 months into my tank, but when you read an Aquarium Pharmaceuticals test, do you hold the tube right up against the card, or up off of it a bit? Readings are totally different. I've been reading them up against the card, but I've seen the LPS do it by standing them up on the card, which is not the same reading as right against it...