To Michael: Microdol-X, when diluted to 1:3, loses most of the effects of high sulfide concentration: reduced speed and sharpness. I used to dilute it 1:2 for more reasonable dev. times (which I had to come up with myself). You still got low contrast with Microdol with increased dev. times? I currently use Xtol and Microphen (for a speed increase) diluted 1:2. I filter all of my chemicals through paper coffee filters. To use one filter per session without contamination I go in this order: developer, rinse filter in water, Heico Perma Wash, stop bath, second fixer, first fixer. I have a filter on the faucet too. This keeps the crud off the negs.(posted 9053 days ago)