Paul(posted 8338 days ago)From memory i think that the varied times that are quoted relate to different dilutions. 4 min sounds like a 1:9 dilution and 6.5 min a 1:14 dilution-both at 20 deg C. The general consensus is that development needs to be a minimum of 5 min so i would suggest that you go for the 1:14 dilution. Hope this helps Andrew