Here is a mistake that I made that might benefit others. Using fresh D76 and other chemicals I ended up with very thin Ilford FP4+ negatives. Finally I discovered that I had misread the online Ilford development chart. The chart has three columns with times for EI of 50, 125 and 200. D76 is way down the list and the column headings were not visible. Using the first column times resulted in underdeveloped negatives, of course. Time is 33% longer for 125 rating. I have printed and highlighted the sheet so I will not make the same mistake again.