Hi i was wondering if anyone can help me as i am having problems doing a test strip. as I am having problems doing a good test strip i have tries 2 seconds, all the way until you reach 10 seconds on the sheet i have also tries 10 seconds up till Twenty But all I get is ever a really light or nothing or just a few little spots when put in the developer I have tried grade 1-2 and 3 and it makes no difference where am I going wrong??