Can anyone tell me what caused these spots? Not the big white dust spots the gray looking spots all over the frame. Film was Ilford HP5 400 expired 1.5 years ago. I used a SideKick film processor and tried a pre wet for the first time. Developer was Kodak HC110 dilution B. The gallon container is collapsable to keep out air. It was 1/2 full of 2.5 month old developer and I filled it up the rest of the way with fresh developer mixed today. Continuous agitation and air dried.